OBJECTIVES:  To analyze the relationship between the change of drug mix for Cephalosporins and their cost increases in order to provide a reference for future research and government policy making on cost of antacids and anti-ulcer medications. METHODS: Build a foundation based on drug DDD unit, analyze the index analysis system of the influence of drug mix of Cephalosporins on drug cost on different levels. RESULTS: The total procurement costs of Cephalosporins for Guangdong province and the purchases of DDD increased by 158% and 120% respectively in 2007-2011. At the same time, the price level declined significantly, the price index calculated by Laspeyres index decreased by 12%. CONCLUSIONS: The amount of drug utilization is the most important factor that caused cost increase, the decline of price inhibits the Cephalosporins drug price growth to a certain extent. Technological innovation is the motivating factor to cause the Cephalosporins drug price to increase. There is a link between the level index of administration route and the rationality of drug use. The competition among different manufacturers is an important factor that affects the total expenditure of Cephalosporins.