Abstract:[Objective] To study the effects of infiltration amount and experimental scale on heterogeneous soil water flow(including both the maximum infiltration depth and the average infiltration depth, preferential flow heterogeneity and the size of preferential flow path), in order to provide theoretical support for efficient use of agricultural irrigation-fertilization, protection of groundwater environment and prediction of hydrological process etc.[Methods] 18 infiltration experiments, using the comassie brilliant blue staining as the dye tracer, were conducted in sand soil with various infiltration amounts(i.e. 1.25, 2.5 and 5.0 cm) and experimental scales (i.e. 0.25 m×0.25 m, 0.5 m×0.5 m and 1.0 m×1.0 m).[Results] (1) Both the maximum infiltration depth and the average infiltration depth increase with the increasing of infiltration amount under the same experimental scale, and the preferential flow heterogeneity increases firstly and then decreases with the increasing of the infiltration amount under the same experimental scale; (2) While under the same infiltration amount condition, the maximum infiltration depth and the preferential flow heterogeneity increase with the experimental scale when the infiltration amount is relatively small but the maximum infiltration depth and the preferential flow heterogeneity keep almost unchanged when the infiltration amount is considerably high; (3) Furthermore, the increasing of infiltration amount and experimental scale both make the preferential flow path expanded.[Conclusion] The infiltration amount and experimental scale have obvious impacts on the heterogeneous soil water flow.