Abstract: Objective To study the synergistic effect on male antifertility of a combined regimen of lowdoes gossypol with steroid hormones. Methods Adult male rats were divided randomly BR> into four groups: group GH, rats were fed orally with GA ［12.5mg/(kgI>&#/I>8226;d)］ and DSG ［0.125mg/(kgI>&#/I>8226;d)］/E ［0.025mg/(kgI>&#/I>8226;d)］/TU［100mg/L(kgI>&#/I>8226;d)］; group G, a single does of GA ［12.5mg/(kgI>&#/I>8226;d)］ was given; group H, DSG ［0.125mg/(kgI>&#/I>8226;d)］/E［0.025mg/(kgI>&#/I>8226;d)］/TU［100mg/(kgI>&#/I>8226;d)］ were administered; group C, rats only received vehicle (1% methyl cellulose). The testis and epididymis were removed at 4,6 and 8 week for counting sperm number，sperm motility and stereological changes of testis tissue. Results Low-dose gossypol with steroid hormones did not have a synergistic effect on reducing testicular weight，sperm production or stereological parameters. However, they did have a synergistic effect on reducing epididymal sperm number and sperm motilit

Key words: Gossypol, Steroid hormone, Male antifertility, Synergistic effect, Rat