This book studies the price discrimination through the drug s market. Using the data from the USA and Chinese drugs markets, we are looking for the factors what might affect the price discrimination. Counting the price per mg/ml and classifying the drugs by the diseases, we find that the price discrimination of the anti-infective drugs is the smallest in both countries, the drugs prices are positively related to the price discrimination, and the standard deviation of the American drug's prices is smaller than the standard deviation of the Chinese drug s prices.