Objective： To discuss the relationship between threatened abortion and laws of seasons and solar terms.Methods：Reviewed 526 cases of patients with threatened abortion.Counted the number and the proportion of patients with threatened abortion in each season and counted the number of patients with threatened abortion in different seasons.Compared the rate of patients succeeding in calming fetus among different seasons.Results：The season of the biggest number of patients with threatened abortion was Spring which was 168 cases accounting for 31.94%of the total patients；the solar term of the biggest number of patients with threatened abortion was Rain Water，followed by Clear and Bright and Start of Spring；no significant difference was found in the comparison of the rate of patients succeeding in calming fetus among different seasons(P＜0.05).Conclusion：The incidence of threatened abortion has a close relationship with laws of seasons and solar terms.Spring，Rain Water，Start of Spring and Clear and Bright are the peak periods.According to the characteristics of Spring，treatment of calming fetus in this period should pay attention to treating body and mind as well as adjusting emotions.The treatment should focus on calming the liver，reinforcing the kidney and calming the fetus.