BACKGROUND The aim of this study was to investigate the effect of Cuscuta chinensis Lam. on germ cell apoptosis in a rat model of unilateral cryptorchidism. MATERIAL AND METHODS Thirty male SD rats were randomly and equally divided into a control group, a model group, and a Cuscuta group (5.0 g/kg/d) (n=10). The rat model of unilateral cryptorchidism in the model and Cuscuta groups was established by removal of the right gubernaculum, while rats in the control group received no treatment. After modeling, rats in the Cuscuta chinensis group were intragastrically administered Cuscuta chinensis extract (5.0 g/kg/d), while rats in the control group and model group were administered an equal volume of normal saline. After 90 days, all the rats were sacrificed and the testicles were separated and weighed, followed by TUNEL staining to detect germ cell apoptosis, flow cytometry to measure JC-1, ROS, and MDA, and Western blot analysis to evaluate the expression of Bax, Bcl-2, and cleaved caspase3. RESULTS Ninety days after the operation, Cuscuta chinensis Lam significantly minimized the damage caused by modeling by increasing weight of testis, reducing the germ cell apoptosis, and enhancing the mitochondrial membrane potential of testicles, as shown by levels of JC-1, ROS, and MDA, as well as elevating the level of Bcl-2/Bax and reducing the level of cleaved caspase3 (P<0.05). CONCLUSIONS Treatment with Cuscuta chinensis Lam reduced the germ cell apoptosis in rats with unilateral cryptorchidism, which provides new insight for the development of cryptorchidism therapy in the future.