Based on the survey of the prevalence of NIDDM in 110 660 people aged 25-74 in 1986, the incidence of NIDDM was investigated in 1990 in 36 471 people (M/F 18,801:17,670) who had normal glucose tolerance and/or plasma glucose concentration less than 6.7 mmol/L 2-hour after breakfast (carbohydrate 80 g) four years ago in Daqing, Heilongjiang province, northeast China. 103 male and 88 female diabetics were diagnosed among the 36 471 subjects from June 1986 to June 1990. This result showed that the annual incidence of NIDDM in this area is 131/100,000 (137 in males, 125 in females), and is 130/100,000 standardized to the 1982's chinese population (95% confidence interval, 94-168/100,000). We may estimate that there would be 754 thousand new diabetics per year in 25-74 years old Chinese if the total population were 1.3 billion in China in the 21st century.