We made an observtion on the breeding behabavior on two groups (1♂3♀ and 2♂3♀) of Asiatic Wild Ass from June 2014 to August 2015 at Inner Mongolia Chaganhada Su'mu, Da'erhan Maoming'an Lianheqi Tenggenaoer District (Baotou City) (41°14′﹣42°40′N，109°16′﹣110°26′E) and the National Nature Reserve for Asiatic Wild Ass (Bayannur City) (41°50′﹣42°27′N，106°15′﹣108°00′E) (Fig. 1, Point A and Point C). We recorded the estrus and mating behavior, prenatal reaction, parturition process and postpartum behavioral expression. Our observation revealed that each male mounted female 4.2 ± 1.7 (n = 14) times and ejaculated 3.7 ± 1.3 (n = 13) times each day averagely. The average sexual solicitation duration (begin from flirting to mounting or one goes away) was 26.6 ± 22.0 s (n = 13), the twitching duration was 10.6 ± 1.9 s (n = 14), and the penis implantation duration was 18.3 ± 8.8 s (n = 13). The mounting interval was 685.7 ± 569.6 s (n = 14), and the ejaculate interval was 924.0 ± 790.0 s (n = 10). The copulatory pattern of Assiatic Ass was with no lock, thrusting, single intromission, multiple ejaculation, and no long time intromission, which belonged to type 11 in Dewsbury's copulatory-patterned system and type 12 in Dixon's copulatory-patterned system. We established the breeding behavior spectrum for the wild and provided some basic data on the breeding behavior based on our observation.