Abstract: Located northeast of the Tibetan Plateau, the Qilian Mountains is an important ecological protective screen and conservation zone, as well as a key water source for the Yellow River basin. However, studies on cloud and precipitation in this region are seriously lacking. Using the observations of 11 Parsivel2 disdrometers in the Qilian Mountains, this paper studied the raindrop size distribution characteristics and the orographic impact in a spring stratiform precipitation case over the Qilian Mountains. This precipitation process was initiated under the influence of a short-wave trough and had a significant temporal and spatial variation. Disdrometer observations show that the mass equivalent diameter ( D_\mathrmm ) was small. The total number concentration of the raindrops ( N_\mathrmT ) and D_\mathrmm would increase and decrease as the elevation becomes higher. The relationship between \mathrml\mathrmo\mathrmgN_\mathrmw ( N_\mathrmw is the intercept parameter of the rain drop size distribution) and D_\mathrmm had featured stratiform precipitation characteristics. In the same D_\mathrmm , there was a higher N_\mathrmw in the Qilian Mountains. For lower elevation sites, there were fewer small raindrops (＜1 mm) than the large raindrops because of the evaporation of small raindrops and the coalescence. Because the sites with a higher elevation were close to the cloud base or in the cloud, the size scale of raindrops became smaller and D_\mathrmm varied little with the rain rate ( R ). The M-P and Gamma distribution fit better for sites with a lower altitude. For sites with a higher altitude, the Gamma distribution describes the spectrum better, while the M-P distribution will overestimate/underestimate the concentrations of smaller/larger raindrops. The μ–Λ (μ and Λ are shape and slope parameters of the rain drop size distribution) relationship for sites with a higher altitude are similar to those in related researches. However, when the Λ is small (<40 mm⁻¹), results will be better for all sites. Influenced by the topography and the relative position between the observational site and cloud base, the Z–R (Z is the radar reflectivity factor) relationship all showed quite different characteristics with other regions or researches.