Abstract Background Feminization of health workforce has been globally documented, but it has not been investigated in China. This study aims to analyze changes in the gendered composition of health workforce and explore the trend in different types of health workforce, health organizations and majors within China’s health system. Methods The data were collected from China Health Statistical Yearbook from 2002 to 2020. We focused on health professionals including doctors, nurses, and pharmacists in health organizations. Trend analysis was employed to examine the change in the ratio of female health workforce over 18 years. The estimated average annual percent change (AAPC) was estimated, and the reciprocals of variances for the female ratios were used as weights. Results In China, health professionals increased from 4.7 million in 2002 to 10.68 million in 2020. Health professionals per 1000 population increased from 3.41 in 2002 to 7.57 in 2020. The ratio of female health professionals significantly increased from 63.85% in 2002 to 72.4% in 2020 (AAPC = 1.04%, 95% CI 0.96–1.11%, P