Reserve selections are often opportunistic rather than strategic and coordinated, and consequently many reserves are ineffective to achieve their intended goals of conservation. Here we assessed the conservation effectiveness of a reserve for the golden snub-nosed monkeys (Rhinopithecus roxellana) with a niche-based approach. We assessed habitat usage of the monkeys in Shennongjia Nature Reserve (SNR) and attributes of 14 environmental variables that could potentially affect the monkeys’ habitat use. Spatial distribution of potentially suitable habitat for the monkeys was then modeled with Maxent, a niche-based model, and conservation effectiveness of SNR was assessed by comparing the current boundary of the reserve with the spatial distribution of the modeled potential habitat and the current habitat area of the monkeys. Only 59% of the habitat area and 61% of the predicted potential habitat area were under the protection of SNR. To improve conservation effectiveness of SNR, we proposed that the current SNR be enlarged by 270 km2. The enlarged reserve would encompass 100% of the existing habitat area plus 89% of the predicted potential habitat area. Using the niche-based approach, we were able to integrate habitat usage data of the target species with that of remote sensing to identify areas potentially suitable as habitat for the species. This information not only can be used for improving conservation effectiveness of existing reserves but also for the effective planning and designing of new reserves.