Few studies have been conducted to explore the independent and combined associations of body mass index (BMI) and physical activity with risk of hypertension in Chinese population. A cross-sectional study of 5291 individuals (aged >= 40 years) selected using multi-stage sampling method was conducted from October 2013 to December 2015. In the present analysis, 55.64% of the participants were women, and the mean age of participants was 55.37 +/- 10.56. Compared with individuals in normal group, the risks of hypertension were nearly double in overweight subjects (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.53-2.05) and more than three times higher in obese subjects (3.23, 2.62-4.13). Multi-adjusted odds for hypertension associated with low, moderate, and high physical activity were 1.44 (1.17-1.86), 1.40 (1.09-1.79) and 1.000, respectively. In comparison with normal weight subjects who reported high levels of physical activity, subjects who reported both low levels of physical activity and obesity showed the highest risk of hypertension (5.89, 3.90-8.88). In conclusion, both elevated BMI and reduced physical activity appear to play an important role in the risk of hypertension among Chinese middle-aged and older population. The risk of hypertension associated with overweight and obesity can be reduced considerably by increased physical activity levels.