This paper is designed for the purpose of examining the relationship between natural disasters including climate change and social change. Specifically, while paying attention to the occurrence of natural disasters in the Goryeo Dynasty in the first half of the 12th century, it examined whether there was a ‘climate crisis’, and tried a new research method to understand the relationship with social change. In the case of disaster records in the first half of the 12th century, not only does the proportion of drought the highest as before, but many disasters related to the cold climate such as hail, frost, and wood ice(木氷) are recorded. It is noteworthy that irregular climate fluctuations, that is, abnormal low or abnormal high temperatures, were occurring during this period, and many disasters were recorded ‘repeatedly’. Such cold climates and irregular abnormal climate fluctuations are the contents of the ‘climate crisis’ in the first half of the 12th century, and it is believed that there is a possibility of an El Nino phenomenon as a cause. The occurrence of natural disasters in the first half of the 12th century directly or indirectly affected human production activities and lives. This fact can be confirmed through the correlation between the occurrence of natural disasters and the trends of famine, disease, and infectious diseases. In addition, it is believed that the occurrence of these natural disasters also affected the social composition or operation, and paradoxically, the damage also affected social development. It is also noteworthy that such cases often appear at a time when a lull reaches some extent, especially after experiencing damage caused by natural disasters.