Nowadays, the world economy is blaming Chinese government for the intervention into foreign exchange market to keep RMB value lower than the market rate and forcing rationalization of the RMB exchange rate. In this paper, we try to test whether the blame can be legitimated. For that, we apply two sets of test methods, linear cointegration tests of Johansen and threshold coingration tests proposed by Hansen and Seo(2002) and test whether the movements of RMB is consistent with PPP theory. We find that the theory does not hold for RMB and Chinese government may not free from the blame. However, we also find that currencies of 4 major asian countries are inconsistent with the theory. The result implies that market intervention is not a problem peculiar to China or that the PPP theory cannot supported by actual data.