Cross-Border distribution temporal and spatial pattern evolutions of population of Wa Nationality from 2000 to 2010 were analyzed by the application of GIS spatial technology in this paper. The results showed that the Wa Nationality was originated in the Awa Mountain Region, and then gradually moved and spread to the surrounding mountainous centering on the Awa Mountain Region. From the view of population spatial distribution map of the Wa Nationality, The population of the Wa Nationality in China was mainly distributed in Cangyuan Wa Autonomous County and Ximeng Wa Autonomous County as the centers, and around the China-Burma borders of eight counties such as Lancang, Menglian, Gengma, Shuangjiang, Yongde and Zhenkan. The population of the Wa Nationality in Burma was mainly distributed in the 2nd Special Zone (Wa State) in Shan State of Burma. The population of the Wa Nationality in Laos was mainly distributed in the central and northern mountains of Laos at altitudes of 500 to 1200 meters, especially centrally inhabited in Boloven Plateau and border mountain region bordering northern Fengshali and Burma. The population of the Wa Nationality in Thailand is mainly scattered in Chiang Mai, Mae Hong Son and other places in northern Thailand.