Cattle domestication and the complex histories of East Asian cattle breeds warrant furtherinvestigation. Through analysing the genomes of 49 modern breeds and eight East Asianancient samples, worldwide cattle are consistently classified into five continental groupsbased on Y-chromosome haplotypes and autosomal variants. We find that East Asian cattlepopulations are mainly composed of three distinct ancestries, including an earlier East Asiantaurine ancestry that reached China at least ~3.9kya, a later introduced Eurasian taurineancestry, and a novel Chinese indicine ancestry that diverged from Indian indicine approxi-mately 36.6–49.6kya. We also report historic introgression events that helped domesticcattle from southern China and the Tibetan Plateau achieve rapid adaptation by acquiring~2.93% and ~1.22% of their genomes from banteng and yak, respectively. Our findingsprovide new insights into the evolutionary history of cattle and the importance of intro-gression in adaptation of cattle to new environmental challenges in East Asia.