采用野外调查法，对甘肃白水江国家级自然保护区内的兰科(Orchidaceae)植物多样性和分布特征进行调查和统计分析。结果表明：保护区内共有兰科植物27属58种，是甘肃省兰科植物种类较为丰富的地区，其中，虾脊兰属(Calanthe R. Br.)和杓兰属(Cypripedium Linn.)为保护区兰科植物的优势属。兰科植物以地生兰为主，共21属52种，分别占保护区兰科植物总属数和总种数的77.8%和89.7%，腐生兰和附生兰较少。国家二级重点保护野生兰科植物15种，占保护区兰科植物总种数的25.9%；中国特有种22种，占保护区兰科植物总种数的37.9%；易危等级及以上(19种)和易危等级以下(39种)兰科植物分别占保护区兰科植物总种数的32.8%和67.2%。保护区兰科植物在水平分布上以铁楼藏族乡的种类最为丰富(35种)，占保护区兰科植物总种数的60.3%；在垂直分布上以海拔(1 400，1 800］ m内的种类最为丰富(31种)，高海拔区域的种类较少。综合研究结果表明：甘肃白水江国家级自然保护区兰科植物资源丰富，中国特有种丰富，保护区生境条件更适宜地生兰生长；兰科植物属级分化明显，水平分布广泛但不均匀，且垂直分布明显。保护区国家二级重点保护野生兰科植物种类与受威胁兰科植物种类重合度较高，亟需开展针对保护区受威胁兰科植物种类的就地保护工作，加大保护力度。

 The diversity and distribution characteristics of Orchidaceae in Baishuijiang National Nature Reserve of Gansu Province were investigated and statistically analyzed by using field investigation method. The results show that there are a total of 58 species belonging to 27 genera in Orchidaceae in the reserve, and it is a region with relatively rich species in Orchidaceae in Gansu Province, among which, Calanthe R. Br. and Cypripedium Linn. are the dominant genera in Orchidaceae in the reserve. Terrestrial orchids are the dominant Orchidaceae, and there are a total of 52 species in 21 genera, accounting for 77.8% and 89.7% of the total genera and species numbers of Orchidaceae in the reserve, respectively, while saprophytic and epiphytic orchids are relatively rare. There are 15 national second-class key protected wild species in Orchidaceae, accounting for 25.9% of the total species number of Orchidaceae in the reserve; 22 species are endemic to China, accounting for 37.9% of the total species number of Orchidaceae; Orchidaceae classified as vulnerable or higher (19 species) and those below vulnerable (39 species) account for 32.8% and 67.2% of the total species number of Orchidaceae in the reserve, respectively. The species are the most abundant (35 species) in Tielou Zang Autonomous Township in horizontal distribution, accounting for 60.3% of the total species number of Orchidaceae in the reserve; in terms of vertical distribution, the species are the most abundant (31 species) at altitude of (1 400, 1 800］ m, species is fewer in high altitude area. The comprehensive research results show that Baishuijiang National Nature Reserve of Gansu Province are rich in Orchidaceae resources and Chinese endemic species, and the habitat conditions in the reserve are more suitable for the growth of terrestrial orchids; the genus differentiation of Orchidaceae is obvious, the horizontal distribution is wide but not uniform, and the vertical distribution is obvious. There is a high overlap between the national second-class key protected wild species and the threatened species in Orchidaceae in the reserve, and there is an urgent need to implement insitu conservation for the threatened species in Orchidaceae and strengthen protection efforts.