Abstract: On the basis o f epidemiolog ical sur vey on diabetes mellitus( DM) in jiangsu province, w e conducted a case control study to investigate the relationship bet ween smoking or drinking and diabetes.Newly diag nosed diabetes and impair ed glucose tolerance( TGT) patients were matched by their ow n contro ls respectively. Our result show ed smoking was related to DM. Those who smo ked more t han 26 cigarettes per dav were in hig her r isk of DM, the odds ratio of ever smokers was 5?? 60. T he morecig ar ettes an individual smoked in a day, the hig her risk he w ould take in DM. We hadn?? t found smo kingw as in r elation with IGT. Drinking habits, unlike smoking, w as proved not to be the r isk factor of DM or IGT acco rding to our study, but if consuming up to 35 kilogr ams pure alcohol per year, one would have a higher risk in IGT.