Rainfall can be partitioned into 3 parts through the vegetable canopy: throughfall

stemflow

and interception. In this study

an experiment was carried out in Pailugou watershed in Qilian Mountains in the arid region of northwest China. In a Berberis diaphana and Caragana tangutica shrub stand

throughfall

stemflow

and canopy interception of 38 rain events were observed from 1 June to 31 September

2014. Then

we analyzed the characteristics of rainfall canopy partitioning and their influence factors. The results showed that: (1) The throughfall

stemflow and canopy interception of individual Berberis diaphana shrub were 175.2 mm (46.3%)

20.8 mm (5.5%) and 182.6 mm (48.2%)

respectively

while those of individual Caragana tangutica shrub were 239.1 mm (65.0%)

15.1 mm (4.1%) and 113.4 mm (30.9%)

respectively. Meanwhile

the interception ratio of Berberis diaphana and Caragana tangutica community were 29.3% and 18.6%

respectively. (2) The amount of throughfall

stemflow and canopy interception of individual Berberis diaphana and Caragana tangutica shrub showed a significant positive linear correlation with rainfall amount (P＜0.01). The relationship of throughfall ratio and interception ratio of shrubs with rainfall amount could be fitted with logarithmic curve (P＜0.05). (3) The critical rainfall amounts for the occurrence of throughfall under Berberis diaphana and Caragana tangutica shrub were 1.2 mm and 0.9 mm

respectively. Meanwhile

stemflow generated when the rainfall in early period was 2.0 mm. (4) The interception ratio for 2 shrubs showed that the maximum values were achieved in September

with the second highest values in July

and the minimum values in June and August. In addition

the stemflow ratio changed slightly from June to August

while it decreased obviously in September.