Abstract: Objective To explore the efficacy of dilatation of ejaculatory duct under semioscope combined with transurethral electrotomy in the treatment for ejaculatory duct cyst. Methods From October 2014 to June 2019, 16 cases with oligospermia or azoospermia caused by obstruction of ejaculatory duct cyst were selected and treated with dilatation of ejaculatory duct under semioscope combined with transurethral electrotomy. Results The semen volume of 16 patients was 0.6 to 1.8 mL before operation, and the fructose of seminal plasma significantly reduced. Among them, 12 cases were azoospermia, and 4 cases were asthenospermia. All patients finished operation successfully and were followed up for at least 6 months. The seminal vesicle glands of 5 patients significantly reduced one year after the operation, and spouses of 4 patients were pregnant successfully at 9 to 12 months after the operation. The amount of semen after operation was significantly higher than that before operation(P<0.05), and the level of fructose in seminal plasma after operation was significantly higher than that before operation(P<0.05). Conclusion Dilatation of ejaculatory duct under semioscope combined with transurethral electrotomy is effective and safe in the treatment for ejaculatory duct cyst.