The breeding biology of the Oriental Pied Hornbill (Anthracoceros albirostris) (Fig. 1) in Xidamingshan Autonomous Nature Reserve in southwestern Guangxi was investigated, and five nests were monitored with direct observation or infrared cameras in two years (2 nests in 2014, 3 nests in 2015). Nesting trees were repeatedly used; nesting tree species were Choerospondias axillaris and Chrysophyllum lanceolatum. The average diameter at breast height of the nesting trees was 73.7 cm (n = 3), and the heights of the nesting cavities was 7.8 m and 9.0 m (n = 2) respectively, the average distance between the nesting trees and plantation/understorey crop was 87 m (0 – 210 m, n = 3), of which two trees grow by the side of trails frequently used by villagers (Table 1). The Oriental Pied Hornbill in Xidamingshan started breeding in late April to late May at the onset of wet season in that region, when female hornbills entered the nest cavities and confined themselves. Females completed their moulting during the confinement period, and emerged with the chicks between mid-July and mid-August. The nestling periods were 89 d and 93 d (n = 2), similar to that of captive pairs in nearby Nanning Zoo (89 days, n = 4). The breeding success rate was 100% (n = 4) and the average number of fledglings was 2.3 ± 0.5 (n = 4) (Table 2). Daily feeding pattern is bimodal, with peaks in the morning and before dusk (Fig. 3), while the daily feeding frequency increased gradually towards fledging of the chicks (Fig. 4). More than 80% of the food items the paired males delivered to their nests were fruits (Table 3). The Oriental Pied Hornbill of Xidamingshan in our study area could tolerate some degree of human disturbance during breeding period and local food resources seemed to be sufficient, but the natural forest was severely fragmented with only scattered big trees. Availability of nest cavity is likely a key limiting factor restricting population growth of the resident Oriental Pied Hornbill. It is recommended to strengthen law enforcement in the reserve and explore feasibility of planting fast-growing, large-girth native tree species and the application of artificial nest box.