Abstract: Data on daytime budget of saiga antelopes (Saiga tatarica) were collected in a colony of multifemale,onemale unit in a 30 ha enclosure in Wuwei,Gansu Province.The state-behaviors were scanned and instantaneous sampled with 5-min intervals in two seasons — the mating season P1,December 2000,including pre-mating (a),mating (b) and post-mating ? periods,and the lactation (P2,May-July,2001).Data processing showed:1)After Plb females increased their time in feeding,and reduced that in lying-out;from P1a to P1c,time in standing successively reduced;within 2 weeks after giving birth,the females separated from the major group,and returned with lambs in the 3rd week.2)The adult male spent more time in moving in P1a than that in P1b,and increased time in lyingout after P1b.3)Sex difference of time budget,especially the feeding and lying-out time,appeared in and after P1b,and the difference could be traced to the differentiation of parental investments - females were the only investors to the offspring since pregnancy.These results implied that supplementary food should increase in the two seasons for the animals better reproduction.