Abstract:The Saiga tatarica, a member of the Bovidae, is classified as critically endangered A2acr ver 3.1 by the IUCN. It was historically distributed in northwest of China and was extirpated in the mid-twentieth century in wild. In order to initially explore the effects of the partial biological indicators for the newborn S. tatarica, the survival ratio, sex ratio, single and double lamb ratios, weight and others were included. From the end of April to the start of May 2018, this study has conducted on-site measuring of 61 newborn S. tataricas in the Gansu Endangered Animal Protection Center which was the only artificial domesticated base of the S. tatarica in China, and has conducted an inductive analysis of the measurements. The results showed that the period of childbirth began from April 25 to May 5, 2018, a total of 61 lambs were delivered during the period. The peak period of lambing production was concentrated from April 28 to May 2 (Fig. 1). The newborn S. tatarica survived 56, with the survival ratio of 91.80%. The newborn male lambs accounted for 40.98% of the total lambs, and the newborn female lambs accounted for 59.02% of the total lambs, and the female-male sex ratio (♀︰♂) was 1.44︰1 (Table 2). The differences were not significant after χ2 test (P > 0.05). The single lamb ratio was 80.33%, the double lamb ratio was 19.67%. The differences were extremely significant between the ratio of single lamb and double lamb (P < 0.01). The average weight of newborn lambs were mainly concentrated in 2.501﹣3.000 kg, and the average newborn weight of male lambs was slightly higher than those of female lambs, the average newborn weight of single lambs was slightly higher than those of double lambs. The differences were not significant that the average newborn weight of the single lamb and the double lamb of the newborn male S. tataricas. The differences were not significant that the single lamb and the double lamb of the newborn female S. tataricas, and the differences were not significant that the total average newborn weight of the single and double lambs and the total average weight of male and female lambs (P > 0.05, Table 3). Those research results provided a reference for the basic research of S. tatarica in China and provided a theoretical basis for S. tatarica population of protection.