【Abstract】 Objective To investigate the effect of Zhixue Zhentong Capsule on the contraction of isolated uterine smooth muscle in rats. Methods 60 SPF female SD rats were randomly divided into blank control group, model control group, progesterone control group, different dose control groups of Duyiwei Capsule (0.2494, 0.4975, 0.9901, 1.9608, 3.8461 mg capsule contents /mL), different dose groups of Zhixue Zhentong Capsule (0.2494, 0.4975, 0.9901, 1.9608, 3.8461 mg capsule contents / mL), 1015 in each group. Rats were intraperitoneally injected with estradiol benzoate for allergic sensitization. After 48 h, the rats were killed and the smooth muscle of the uterus was removed, and then oxytocin was added to induce constriction in the smooth muscle of the uterus. Finally, five different final concentrations (0.2494, 0.4975, 0.9901, 1.9608, 3.8461 mg capsule contents /mL) of Zhixue Zhentong Capsule were added successively. The contractile changes of uterine smooth muscle before and after administration were recorded, and the mean tension, contractile frequency and activity were analyzed. Results No significant effect of Zhixue Zhentong Capsule on the contraction of uterine smooth muscle was observed in terms of the average tension, frequency and activity (P＞0.05). Zhixue Zhentong Capsule (3.8461 mg capsule content/mL) can significantly inhibit oxytocininduced contraction of uterine smooth muscle in rats, showing a decrease in average tension (P＜0.05), but no significant effect was noticed on contraction frequency and activity (P＞0.05). Conclusion Zhixue Zhentong Capsule can directly inhibit the contraction of isolated uterine smooth muscle in rats, which could be one of the mechanisms for clinical treatment of dysmenorrhea.