This paper examines the co-movements among China, Hong Kong and Taiwan stock markets during the period from January 4, 2000 to December 29, 2017. This paper analyzes how the co-movements of the Chinese, Hong Kong and Taiwan stock markets changes from the global financial crisis and from the major changes in the stock market system in China. The analysis used daily data of China Shanghai Composite Stock Index (CSI), Hong Kong Hang Seng Index (HSI), Taiwan Stock Index (TSI) and US S&P500 Stock Index (SPI). In this paper, the analysis period is divided into the period from the global financial crisis to the period from the major changes of the stock market related system such as stock index futures trading and Shanghai-Hong Kong Stock Connect, This paper has examined in more detail how the phenomenon of co-movements among the Greater China stock markets is changing. The results of this study are summarized as follows. First, as a result of the analysis on the whole analysis period, the Shanghai Composite Stock Index has a positive (+) relationship with the Hong Kong Hang Seng Index and the Taiwan Stock Price Index, but it has a negative relationship with the US S&P500 Index respectively. And the Shanghai Composite Stock Index is more influenced by the Hang Seng Index than the Taiwan Stock Index. The Hong Kong Hang Seng Index and the Taiwan Stock Price Index both showed a positive (+) relationship with the Shanghai Composite Stock Price Index, the Taiwan Stock Index (Hong Kong Hang Seng Index) and the US S&P 500 Index. The Hong Kong Hang Seng Index is the most affected by the US S&P 500 Index, and the Taiwan Stock Price Index is most affected by Hong Kong Hang Seng Index. Second, in the period after the global financial crisis, the correlation between the Shanghai Composite Stock Price Index, Hong Kong Hang Seng Index, Taiwan Stock Price Index and US S&P 500 Index has been strengthened more than before the global financial crisis. In the Hong Kong Hang Seng Index, the influence of the Taiwanese Stock Price Index declined sharply after the global financial crisis, and the impact of the Shanghai Composite Stock Price Index and the US S&P 500 Index increased, especially in connection with the Shanghai Composite Stock Price Index. The Taiwan Stock Price Index is still influenced by the Hong Kong Hang Seng Index and the US S&P 500 index after the global financial crisis, but the impact of the Shanghai Composite Stock Index has increased significantly. Third, in the Shanghai Composite Stock Index, the influence of Hong Kong Hang Seng Index and US S&P 500 Index decreased in the pre-Shanghai-Hong Kong Stock Connect period compared to the pre-stock index futures trading period. In the post-Shanghai-Hong Kong Stock Connect period, the influence of the Taiwanese market index decreased while the impact of Hong Kong's Hang Seng index increased. As a result, the Shanghai Composite Stock Price Index after-Shanghai-Hong Kong Stock Connect showed a stronger correlation with the Hong Kong Hang Seng Index. Fourth, during the post-Shanghai-Hong Kong Stock Connect period compared to the period before the stock index futures trading, while the influence of the Shanghai Composite Stock Price Index and the US S&P 500 index to the Hong Kong Hang Seng Index increased, but the influence of the Taiwanese stock index to the Hong Kong Hang Seng Index decreased significantly. The Hong Kong Hang Seng Index was much less affected by the Taiwanese stock index in the post- Shanghai-Hong Kong Stock Connect period, and the S&P 500 index fell slightly, not significant, but the impact of the Shanghai Composite Stock Price Index on Hong Hang Seng index increased significantly. Therefore, since the Shanghai-Hong Kong Stock Connect, co-movements between the Hong Kong Hang Seng Index and the Shanghai Composite Stock Index have been further strengthened. Fifth, the Hong Kong Hang Seng index had the greatest influence on the Taiwanese stock index during the period before the stock index futures trading, but its influence declined significantly before and after the Shanghai-Hong Kong Stock Connect. In addition, the impact of the China Shanghai Composite Stock Index on the Taiwan Stock Index also fell sharply after Shanghai-Hong Kong Stock Connect, so that the influence of the China Shanghai Composite Stock Index and the Hong Kong Hang Seng Index on the Taiwan Stock Index decreased significantly and not significant. As a result, the US S&P 500 index only had a positive effect on the Taiwanese stock index after the Shanghai-Hong Kong Stock Connect period. Sixth, China Shanghai Composite Stock Index, Hong Kong Hang Seng Index, and Taiwanese Stock Index are more sensitive to bad news than good news. And in all periods, the Taiwanese stock index was significantly decreased when the Hong Kong Hang Seng index volatility increased. As a result of the empirical analysis of this paper, after the implementation of the Shanghai-Hong Kong Stock Connect in China, the Shanghai and Hong Kong securities markets have not been accompanied by further incentive to reduce the risk of investment portfolio due to international diversification. On the other hand, the Taiwanese stock market has been able to reduce the risk of the investment portfolio due to the international diversified investment since the stock exchange of the Chinese stock market and the Hong Kong stock market has disappeared after the implementation of the Shanghai-Hong Kong Stock Connect in China. Therefore, international investors investing in the global stock market will need to apply these results to international diversification. As a result, Hong Kong's Hang Seng Index and the Taiwan Stock Price Index are in line with the US stock index and the S&P500 stock index, while the Shanghai Stock Price Index is based on the Hong Kong Hang Seng Index, It is found that there is a positive correlation between the S&P 500 index and the positive S&P 500 index. The Shanghai Composite Stock Price Index and the Taiwan Stock Price Index were the most influenced by the Hong Kong Hang Seng Index. However, Hong Kong's Hang Seng Index was the most affected by the US S&P 500 index. However, Hong Kong's Hang Seng Index was the most affected by the US S&P 500 index. In addition, the correlation between the Shanghai Composite Stock Index, the Hong Kong Hang Seng Index, the Taiwan Stock Price Index and the US S & P 500 Index has been strengthened in the post-global financial crisis period before the global financial crisis. In the case of the Taiwan Stock Price Index, the correlation between the Shanghai Composite Stock Index and the Hong Kong Hang Seng Index after Shanghai-Hong Kong Stock Connect decreased sharply and the US S&P 500 positive effect on the Taiwan Stock Price index. Finally, both the Shanghai Composite Stock Price Index, the Hong Kong Hang Seng Index and the Taiwan Stock Price Index all responded more sensitively to negative news than to good news. The results of this empirical analysis show that it is possible to derive more meaningful results by analyzing the analysis period based on the important changes of the securities system rather than the analysis based on the global financial crisis. In this paper, we analyzed the changes in co-movements among the stock market in China, Hong Kong, and Taiwan, and analyzed how the changes in the stock market related to the Chinese stock market, especially after the Shanghai-Hong Kong Stock Connect. However, this paper fails to analyze the changes in the co-movement of the stock market after the implementation of the Shenzhen-Hong Kong Stock Connect system in December 2016 due to lack of time series data. Future studies are expected to further analyze the changes in the co-movements among the Greater China stock markets after the Shenzhen-Hong Kong Stock Connect.