PIP: This article discusses the sex ratio at birth in Tibet Autonomous Region, China. Data were obtained from the 1982 and 1990 China Censuses. Tibet's sex ratio for the entire population increased from 97.76 males/1000 females to 100.16 during 1982-90. The sex ratio at birth increased from 99.42 to 100.31 during the same period. 95.48% of Tibet's total population are of Tibetan nationality. The sex ratio of the Tibetan population was 97.45 in 1990. The sex ratio at birth of the Tibetan population was 99.44. The sex ratio at birth among ethnic Han was stable at 106 males/100 females. The low sex ratio in Tibet reflects the lack of bias against females. Tibetan's do not regard men as superior to women. The sex ratio at birth of the Tibetan population was 96.42 in Lhasa, 100.48 in towns, and 100.10 in rural areas. The sex ratio of Tibetan children aged 1-4 years was lower than the corresponding national figure. The sex ratio of children aged 5-14 years fluctuates around 102. There was some variation between urban and rural children aged 10-14 years because many boys were sent to study in middle schools or Tibetan classes in other provinces or cities after 1985. Women outnumber men, which makes for difficulties in mate selection. The low sex ratio is attributed to geographical, historical, ethnological, and socioeconomic factors.