Abstract: The occurrence of obesity increased almost two folds in the last decade，meanwhile the expense exhausted directly or indirectly by obesity and its complications reached about 10% of the overall state′s health expenditures. Besides its cardiovascular complications, obesity has significant negative effects on the reproductive system of both men and women，which was confirmed by animal experiments in male and female rodents. Obesity is a risk factor of prostatic cancer，sexual dysfunction, and the declined sperm quality, in males. Obesity is a risk factor of PCOS in females, the declined oocytes quality, and lowered fertile ability. Moreover，obesity has some severe detriments on the growth and development of children and teenagers. In this review，we elucidated the effects of obesity on reproductive endocrinology and metabolism，morphology of reproductive organs，sexual ability，and development of reproductive cells.

Key words: Obesity, Male, Female, Reproduction