In November 17 2014，the mechanism of Shanghai-Hong Kong Stock Connect marks began to work. The scheme connects the Shanghai and Hong Kong stock markets for the first time，allowing investors on both sides to trade and settle shares in the other’s market. Meanwhile it is a big step for China financial market reform. The new scheme will push cooperation between Shanghai and Hong Kong stock markets，and make help in building international finance center for both two metropolises. It’s a significant breakthrough in the opening of China’s capital market，playing great role for RMB internationalization. The new scheme must have some flaws that will make risk for the stabilization of Shanghai and Hong Kong stock markets. The regulators in Chinese Mainland and Hong Kong must make good cooperation to improve the levels of supervision laws and regulations to control the potential risks.