In this paper,the plasma gonadotropins including follicle-stimulating hormone(FSH),luteinizing hormone(LH),gonadal steroids testosterone(T),estradiol(E₂)and progesterone(P)of freshly captured Four Eye-spotted Turtle(Sacalia quadriocellata)were measured using a radio-immunoassay(RIA)method.The result shows that:The reproductive hormones in plasma displayed a distinct seasonal cycles.The plasma gonadal steroids levels are correlation to environmental temperature,as highest during summer and autumn,lowest in winter.Plasma T elevated during the period gonadal maturation and spermatogenesis occur.In female,there was a preovulatory LH surge and T rise during mating period,which probably is related to receptivity and coincided with ovarian maturation.Female E₂ levels increased prior to mating season and appeared to stimulate vitellogenin production by liver.A sharp surge of P displayed during mating period(autumn)which coincided with the timing of ovulation.