Background and Purpose- Risk assessment is essential for the primary prevention of stroke. However, the current available tools derived from Chinese populations are insufficient for individualized 10-year and lifetime stroke risk prediction. Our study aims to develop and validate personalized 10-year and lifetime stroke risk equations incorporating 4 large Chinese cohorts. Methods- We used 2 prospective cohorts of 21 320 participants with similar survey protocols as the derivation cohort to develop sex-specific 10-year and lifetime stroke risk equations. Two other independent cohorts with 14 123 and 70 838 participants were used for external validation. In addition, the performance of the 10-year stroke risk equations among participants aged ≥55 years was compared with the new Framingham Stroke Risk Profile. Results- The sex-specific equations for predicting 10-year stroke risk had C statistics being 0.810 for men and 0.810 for women, with calibration χ2 being 15.0 (P=0.092) and 7.8 (P=0.550), respectively. The lifetime stroke risk equations also showed C statistics around 0.800 and calibration χ2 below 20 for both sexes. In the validation cohorts, we found good agreement between the observed and predicted stroke probabilities for both the 10-year and lifetime stroke risk equations. Further compared with the new Framingham Stroke Risk Profile, our 10-year stroke risk equations displayed better prediction capability. In addition, based on lifetime stroke risk assessment, 5.7% of study participants aged 35 to 49 years old were further reclassified as high risk, who were initially categorized as low 10-year risk. Conclusions- We developed a well-performed tool for predicting personalized 10-year and lifetime stroke risk among the Chinese adults, which will facilitate the further identification of high-risk individuals and community-based stroke prevention in China.