Objective To investigate the influence of Lamotrigine (LTG) on sex hormone, seminal fluid and sexual function in male epilepsy patients. Methods The blood sex hormone levels and sperm quality were detected in 20 normal controls and 16 male epilepsy patients in Epilepsy Center of Sichuan Province People's Hospital from April 2015 to November 2016. All participants were detected before taking medicine and after being treated with LTG monotherapy for 1 year. The international index of erectile function-5 (IIEF-5) was employed to assess the sexual function in the groups above, and the results were compared. Results Compared with the control group, the total number of sperm, the rate of forward movement, survival, normal sperm and the score of IIEF-5 in the untreated group were less (P<0.05). LTG treatment group's sperm parameters and the score of IIEF-5 seemed improve, but there was no statistically significant difference (P>0.05). There was no significant difference in sexual hormones between the groups above (P>0.05). Conclusions Semen quality and the score of IIEF-5 in epileptic male decline more easily; LTG might improve the semen quality and sexual function, but no significant difference has being found.