To identify and evaluate the medicine use patterns of asthma patients in China, and to analyze the medical expenses of asthma patients, so as to provide reference for clinical rational use of medicine. Methods Our data were collected from 20 hospital information system (HIS) in China. Adult patients diagnosed with asthma from January 1st in 2013 to December 31st in 2016 in the system were recruited and were included in inclusion and exclusion criteria in our study. We extracted the medicine use patterns and then use the classifier to classify the medicine use patterns. We analyzed medical expense of asthma patients by using the chain of medicine use for the unit. Results A total of 153,868 asthma patients were included in this study, including 135,079 outpatients and 22,500 inpatients. In the modes of single medicine treatment mode and long-term medicine treatment mode, asthma outpatient treatments were both dominated by single medicine treatment. In the long-term medicine treatment mode, outpatients were mainly focused on stable medicine use, and the number inpatients of single medicine treatment was similar to those of the combined medicine use mode. In addition, the single medicine treatment mode was the mainly used for J45.1 and J45.9 diseases, and the combined medicine use mode was the mainly used for J46 diseases. The most common treatment mode for outpatients was the stable use of budesonide formoterol, and the most common treatment mode for inpatients was monotherapy with doxofylline. Among the top 10 chains of asthma outpatients, the proportion of the average cost of asthma drugs per time in the average total cost per time were both high, among which the highest was 75.9% and the lowest was 21.5%. Among the top 20 chains of asthma inpatients, the proportion of the average cost of asthma drugs per time in the average total cost per time areboth high, among which the highest was 5.4% and the lowest was 0.3%. Among the top 20 chains of asthma inpatients, the proportion of the average cost of asthma medicines per time in the average total cost per time was relatively low, among which the highest was 5.4% and the lowest was 0.3%. Among the common medicine use patterns of inpatients, medicine costs of asthma per time were the highest among doxofylline, montelukast sodium and budesonide combined. Conclusion The medicine treatment of asthma patients in China is dominated by western medicine, and the medicine use patterns are relatively complex. The medicine use combination is relatively dispersed. And the medicine expense in the total medical expense of outpatients is higher than that of inpatients.