Objective：To observe the negative effect of androgen on lactate production in human granulosa cells，meanwhile，to explore the follicular dysplasia in polycystic ovary syndrome （PCOS） with hyperandrogenism influenced by the reduced lactate. Methods：The human granulosa cell line-KGN cells were cultured in vitro and treated with different concentrations of testosterone（10-10-10-6 mol/L）for different time（0~48 h）. The content of lactate in culture supernatant was measured. The mRNA levels of LDHA and LDHB were quantified by real-time PCR. The protein expression of LDHA and LDHB were detected by Western blot. Results：After treated with 10-6，10-7 and 10-9 mol/L testosterone for 24 h，besides，10-8 and 10-9 mol/L testosterone for 24 h or 36 h，the contents of lactate in the supernatant were significantly decreased（P < 0.05）. The mRNA and protein expression level of LDHA and LDHB significantly decreased after treated with 10-7 or 10-9 mol/L testosterone for 24 h（P < 0.05）. Conclusion：Excess androgen can suppress the lactate production in human granulosa cell by inhibiting LDH，which may be related to follicular dysplasia in PCOS.