Abstract: 【Objective】In this study, the characteristics of throughfall and the factors influencing it were examined at the scale of individual Berberis diaphana shrubs in the small watershed of Pailugou, the Qilian Mountain. The findings will facilitate quantification of the ecohydrological functions of the shrub in the Qilian Mountain. 【Method】On the basis of an investigation of population characteristics, three representative individuals of B. diaphana were selected as sample shrubs on the lower part of a slope at an elevation of 2 600 m. Three radial sections along the branch radial direction were set up for each sample shrub and containers were installed at each radial section to collect the throughfall from each rainfall event. The throughfall for each rainfall event and parameters of canopy structure were measured. Based on these measurements, then we analyzed the relationship between throughfall and the canopy parameters. 【Result】① During the entire experimental period, the mean throughfall ratio of individual shrubs was 55.1%. However, at some sample sites, a throughfall ratio of greater than 100% was observed. This latter observation could be attributed to the fact that rainfall is concentrated by the canopy. ② The increasing throughfall of B. diaphana shrubs showed a significantly positive linear correlation with the increasing rainfall amount(P <0.01); however, the relationship between the throughfall ratio and the rainfall amount could be fitted with a logarithmic curve(P <0.05). ③ With respect to the horizontal structure of the canopy, the mean throughfall ratio increased from 25.93% at a distance of 10 cm from the shrub core to 74.45% at a distance of 90 cm from the shrub core. The largest increment in throughfall ratio was recorded at a distance of 50-70 cm from the core, which accounted for 41.19% of the total increment for the distance of 10-90 cm from the shrub core. The mean throughfall ratio decreased with increasing canopy thickness. Leaf area index(LAI)affected the throughfall ratio to some extent, with the effect being stronger when the rainfall was light. 【Conclusion】The characteristics of canopy structure, such as canopy thickness, LAI and branch angle, are key factors influencing the spatial distribution of throughfall in B. diaphana shrubs.