Objective To investigate the epidemiologic factors associated with the age of natural menopause and menopausal symptoms in a large population at age of 40 to 65 years in Jiangsu Province.Methods From May 2010 to Oct.2011,a total of 20 275 women (40 to 65 years) attending health examination in Jiangsu Province were enrolled in this cross-sectional study.A structured questionnaire was used to collect data of demographics,menopausal status,chronic diseases,reproductive history.Also the menopausal symptoms were evaluated by Kupperman menopause index (KMI).Cox proportional hazards regression model and Logistic regression were performed to identify risk factors for earlier age of natural menopause and menopausal symptoms,respectively.Results The overall median age at natural menopause in Jiangsu women was 50 years.Lower educational level,poor economic status,lower body mass index (BMI),age at menarche less than 14 years,nulliparity and smoking were associated with earlier onset of natural menopause (P ＜ 0.05).The most frequently symptoms in perimenopausal women were fatigue (46.84％,1880/4014),insomnia (44.67％,1793/4014) and muscle/joint pain (43.80％,1758/ 4014),while sexual problems (57.06％,3463/6070),muscle/joint pain (53.30％,3235/6070) and insomnia (51.03％,3097/6070) were predominant symptoms in postmenopausal women.After adjusting for confounding factors,it was revealed that women with poor educational background,low income,divorce,higher BMI,higher parity,and smoking presented positive correlation with menopausal symptoms (P ＜ 0.05).Conclusions The study suggested that an estimate of median age at natural menopause were 50 years in Jiangsu women.The main factors contributing to earlier onset of menopause and menopausal symptoms were lower educational level,poor economic status,and smoking.Moreover,there were different menopausal symptoms between perimenopausal and postmenopausal women,which provided the important insights for physicians to prevent and treat menopause symptoms in their clinical practice.