The rock fragment which is widespread in the mountain forest soils, deeply affects the characteristics of soil water movement and soil macropores. However, this has been less studied in forest hydrology, although it is an important factor related with hydrological process. Based on the definition that macropores include the soil pores between field capacity and saturated water content, the rock fragments content and the macropore characteristics (radius, density, and area proportion of macropores) as well as their relations were studied, and their effects on the water effluent were evaluated in the plots with typical vegetation forms in a small watershed of Xiangshuihe, south side of Liupan Mountains in northwest China. The results indicate that the steady effluent rate is markedly affected by the mean radius and the density of macropores, especially the density of macropores with radii >1.4 mm. Though the macropores with radii >1.4 mm make up only 686% of the total density, they contribute 67.4% of the variability of the steady effluent rate. The area proportion of macropores, as a parameter synthetically reflecting the effects of radius and density of macropores, can better explain the variability of steady effluent rate. The steady effluent rate is markedly related with the area proportion of soil macropores, in a linear relation with a high determination coefficient (R2=0.8361). However, the relation between the content of rock fragments and steady effluent rate is complicated. In the main root zone of soil layer of 0-60cm, the steady effluent rate increases with the volumetric content of rock fragments until it reaches 15%, and then decreases with the rock fragments content; while the relation in the soil layer of 60-80cm is opposite. The increase of the volumetric content of rock fragments in soils induces a increased mean radius of macropores, especially the increased density of macropores with radius > 1.4 mm, but less effect on the density of macropores with radius <1.4 mm. This means the effect of rock fragments on water effluent rate (macropore flow) is operated by affecting the characteristics of soil macropores in a certain extent, such as the radius and density of macropores. The steady effluent rate varies with soil depth: firstly it decreases from soil surface to deeper layer in the main root zone of 0-60cm, and then increases with soil depth in the layers of >60cm. This is because the macropores and steady effluent rate are more affected by the soil improvement effect of vegetation in the main root zone, while more affected by the increasing rock fragment content in deeper soil layers.