We used radio telemetry to provide the first information concerning home range size of Hainan Partridge Arborophila ardens, a vulnerable species endemic to Hainan Island, China, in both a fragmented and a continuous natural rainforest. Both the monthly and daily home range sizes of the population in the fragmented rainforest were significantly larger than those in the continuous rainforest, with no difference between males and females. Fragmentation reduced habitat quality and thus may have forced the partridges to forage over a wider range, which may threaten their survival.