Vocalizations of Hainan partridges (Arborophila ardens) during the breeding season were studied, by making use of playback experiments, in Yinggeling Nature Reserve, Hainan Island, China. Both males and females were found to crow and to produce duet calls during the breeding season, and there was a sex difference in crowing as shown by spectrogram analyses. Both sexes responded strongly to simulated intrusion from pairs of conspecifics. However, it was found that males responded to intrasexual intrusion to a greater extent than to intersexual intrusion. Moreover, females responded strongly to both intra- and intersexual intrusion. Female-female response is proposed as a behavioral mechanism that favors monogamy in the Hainan partridge, and a generally high response to any kind of vocal stimuli indicates that females may play an important role in territory defense in this species. To our knowledge, this is the first report for female crowing in the genus Arborophila, and the second case for female crowing in the family Phasianidae.