Abstract: Adult northern grass lizards (Takydromus septentrionalis) were collected at Mt.Xiaohe,Hangzhou in three periods of the breeding season,2001.They were dissected to determine sex,and storages of lipids in abdominal fat bodies,carcass,tail and liver.According to the stage of egg development (non-vitellogenetic follicles,yolked follicles,and oviductal eggs),females started vitellogenesis in later March (T1),produced eggs of the first clutch in early May (T2),and partly (37% of the sex) ceased reproduction in mid-June (T3).From T1 to T2,the abdominal fat body of females decreased from 17.3 mg on average to zero,and that of males changed from 6.3 mg to 0.8 mg.The decline of the lipid in females was 3 times of that of males.However,there was no significant change in lipid contents of the carcass,tail and liver in the three periods.It is very likely that the abdominal fat body of females is used for the first clutch of eggs,and earlier production of eggs means more clutches in the season and higher reproductive success.