Abstract： Objective:To investigate the effect of laparoscopic ovarian cystectomy on anti-Mullerian hormone (AMH) level, ovarian response to gonadotropin stimulation and pregnancy rate for in vitro fertilization (IVF) patients with benign ovarian cysts.Methods:Patients with benign ovarian cysts who were admitted for cystectomy and had undergone IVF treatment were enrolled in the study. There were 373 participants with ovarian cysts underwent laparoscopic ovarian cystectomy in the experimental group. According to duration of post-surgery, there were four sub-groups: 1 year post-surgery (1Y POST), 2 years post-surgery (2Y POST), 4 years post-surgery (4Y POST) and ≥5 years post-surgery (≥5Y POST) in the experimental group. According to histopathologic types of ovarian cysts, there were two sub-groups: ovarian endometriotic cysts and ovarian non-endometriotic cysts. Two hundreds and three patients with no history of ovarian cysts and ovarian surgery were in the control group. The level of AMH and basic concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), estradiol (E 2) were measured. Antral follicle counts (AFC) were calculated. There were other study variables: total dose of gonadotropins, duration of ovarian stimulation, the number of oocyte retrieved, the number of embryo obtained, blastocyst transfer rate and pregnancy rate. Results:The control group was matched as closely as possible to the experimental group, including age, body mass index and menstrual cycle (all P>0.05). Compared to the women in control group, the women in ovarian endometriotic cystectomy sub-group had significantly higher levels of basal FSH and basal P, lower level of AMH (all P<0.05); the women in ovarian endometriotic cysts sub-group had significantly higher dose of gonadotropins (all P<0.05); the women in ovarian endometriotic cysts ≥5Y POST sub-group had significantly lower number of oocyte retrieved, lower number of embryo obtained, lower blastocyst transfer rate, and lower pregnancy rate (all P<0.05). Compared to the women in control group, the women in ovarian non-endometriotic cysts sub-group had a significantly higher level of basal FSH and basal P (all P<0.05). The women in ovarian non-endometriotic cysts sub-group had lower level of AMH, higher dose of gonadotropins, lower number of oocyte retrieved, lower number of embryo obtained, lower rate of blastocyst transfer and lower rate of pregnancy than the control group but there were no statistically significant differences among them (all P>0.05). The women with unilateral ovarian endometriotic cysts had significantly lower number of oocyte retrieved on the side of surgery than another side ( P<0.05). Conclusions:In short term laparoscopic ovarian cystectomy has no significant effect on ovarian reserve. But with long-term follow-up ovarian reserve, ovarian response to gonadotropin stimulation and pregnancy rate are decreased. The effect of laparoscopic ovarian cystectomy in benign cysts on ovarian is associated with whether or not it is the surgical side.