Objective To explore the relationship between baseline blood pressure and new-onset diabetes (NOD) in northern China.Methods Prospective cohort study method was used.A total of 101 510 workers took part in the health examination during 2006 to 2007.Of them 90 322 participants were enrolled from the observation population,with fasting blood glucose (FBG) ＜7.0 mmol/L,no history of diabetes,no treatment of hypoglycemic agents,and with complete baseline blood pressure and FBG data.Those,who did not participate in the health examination during 2008-2009 or 2010-2011,and had incomplete FBG data,or had cancer,or died were excluded.Finally,51 631 participants were included into the statistical analysis.According to the data collected during health examinations in 2006-2007,the participants were divided into three groups:normotensive (＜ 120/80mmHg,1 mmHg=0.133 kPa) prehypertensive (120-139/80-89 mmHg),and hypertensive(≥ 140/90 mmHg or using antihypertensive agents).The new-onset diabetes was defined as FBG ≥ 7.0 mmol/L,or having history of diabetes,or using hypoglycemic agents.Kaplan-Meier method was used to draw survival curve,and log-rank test to examine.The relationship between baseline blood pressure and NOD was estimated by multivariate Cox hazard regression model analysis.Results (1) During a median 4.04 year of follow-up,3 917 had NOD.The incidences(/ 1 000 person-years) of NOD in normotensive,prehypertensive,hypertensive groups were respectively 10.41,16.28,and 24.46,men 12.70,17.34,26.79,women 6.30,12.41,24.89,P for trend ＜0.01).(2) Multivariate Cox regression model analysis showed that compared with normotensive group,the prehypertensive and hypertensive groups had an increased risk of NOD after adjusting for age,gender,body mass index,high-sensitivity C-reactive protein,high-density lipoprotein-cholesterol,triglyceride,total cholesterol,FBG,smoking,drinking,physical activity,and family history of diabetes.The corresponding hazard ratios (95％ CI) were 1.19 (1.07-1.33) and 1.35 (1.21-1.50).After adjusting the above factors in men and women,the impact of blood pressure on NOD remained statistically significant,particularly in women.Conclusion Increased blood pressure increases the risk of diabetes,particularly in women.