objective: To analyze the current situation of drugs with high price differences before and after the abolition of drug price control, and then explore its causes. Methods: We used big data of drug price monitored by Beijing Municipal Bureau of Health in 2014 and 2017. More than 1.2 million drug price data from 16 provinces were selected. Different software were used to organize and analyze the data, and also used to screen the data to get effective drug price differences data. Descriptive analysis and chi square test were used to analyze drugs with high price differences. Result: The average price differences of all drugs were 59.5% and 76.8% in 2014 and 2017. Drugs with high price differences accounted for 1.47% and 2.63% in 2014 and 2017. Among those high price differences drugs, 42.7% and 38.2% drugs belonged to national essential medicines list, respectively. And non-Chinese patent medicine accounted for 77.9% and 72.0% in 2014 and 2017. Heat-clearing prescriptions was the main preparation of Chinese patent medicine, while antimicrobial drugs was the most common type of non-Chinese patent medicine. According to the data of 2014, the proportion of regular oral dosage drugs was 54.6%, and that of injections was 30.8%. In 2017 data, oral dosage drugs and injections accounted for 53.8% and 27.7%. In 2014, 70% of the drugs with high price differences were sold in developed areas, and 60% in 2017. There were 94.6% and 96.4% drugs sold in retail and chain pharmacy, much higher than those in hospitals. Conclusion: After the deregulation, the situation of high drug prices still exists, even more serious. It is difficult to curb the high drug prices only by market-oriented control measures. More perfect policies are needed to control the price of drugs within a reasonable range.