The price difference of the Chinese dual-listed companies is a interesting issue. The price of the same asset should be consistent after risk-adjusted, but there is an obvious difference between A-share and H-share which the same company¡¦s shares listed in the Shanghai or Shenzhen Stock Exchange and Hong Kong Stock Exchange. This study found that not only liquidity, demand, required risk premium, and information asymmetry can lead to the price difference, but also manipulation, investor¡¦s preference, and the market emotion. This also verified the investors are more speculative in China than the investors in Hong Kong. Besides, this research analysis the price difference ratio form the viewpoint of valuation, the difference ratio provides a way to understand whether the stock is undervaluation or overvaluation. Finally, this study discussed the Taiwan Depository Receipts. The result indicated that most of the factors which influence the price difference between A-share and H-share also affected the price difference between TDR and the original share. The difference ratio between TDR and original share can also provide some information about the stocks are undervaluation or overvaluation.