OBJECTIVE： To provide reference for guarantee the supply of short-landed drugs. METHODS： A questionnaire survey was conducted to investigate the drug shortage in 40 medical institutions in China. Based on the survey data， the econometric model was built to analyze the reasons for drug shortage in medical institutions. RESULTS： 40 questionnaires were issued and 26 valid questionnaires were collected with effective recovery rate of 65.0％. The institutions surveyed received 87 samples of short-landed drugs， involving 33 drugs； 82.8％ of short-landed drug samples were in short supply for more than 3 months， and even 21.8％ short-landed drug samples were in short supply for more than 12 months. The common reasons for drug shortage mainly included： not entering the provincial bidding directory； adopting the government pricing method； being redistribution system； not establishing provincial normal reserve mechanism. In addition to common reasons， there were some personality reasons for drug shortage based on the necessity of clinical needs， drug attributes and drug price. CONCLUSIONS： There are many reasons for the shortage of drugs in medical institutions. There are both common causes and personality reasons. It is necessary to solve many problems of drug shortage from the source， and it needs many policies and systems to cooperate with them.