The purpose of this study was to examine the conditions of drug use and the find the main factors that lead students to start and select drugs in their circumstances. The "other drugs" in this study means analgesics, hypnotics, stimulants, tranqualizers, and drinks including caffeine. The sample was 1,900 students and 1,412 responses were analyzed. Variables in the study included prescription provision by parents, drug use by friends, attitudes to drugs, drinking and smoking activities, and poly drug use. Analysis of the data was done using descriptive statistics, chi square, and to find the determinants on other drug use, multiple logistic regression was performed. Data were analysed by SAS/PC programs. Of the subjects 86.6% of the students have had experienced with alcohol and 49.8% of them continue to use it, and 37.9% of the students have had experienced with smoking and 22.1% of them continue to smoke. The rates of using other drugs were as followed; analgesic 33.3%, hypnotics 4.3%, sedatives 4.4%, stimulants 8.7%, and 242 students have had experienced with more than two different kinds of drugs of the same time including alcohol and smoking. With the exception of alcohol and smoking, 126 students were continuing to use more than two different kinds of drugs. And 2.3 kinds of drugs were the average that the being used at the same time by poly drug users, alcohol and smoking excepting. In conclusion, the determinants of other drug use can be summarized as ploy drug use, drug use by friends, obedience to drug prescription of parents, and time of first using drugs.