A hillslope infiltration-runoff model in earth-rock mountain regions was established, including vegetation interception, depression storage, infiltration, subsurface flow, and concave and fissures storage of the bed rock. Based on the analysis of the underlying surface characteristics in earth-rock mountain regions, the volume fraction of rock fragments in soils was introduced to qualify their impacts on infiltration. The concave and fissures storage of the bed rock was also considered in the present model. Field experiments on runoff yield and confluence of natural precipitation were carried out for model verification, and the simulation results of the present model were compared and analyzed with that of existing hillslope infiltration-runoff models. The results show that compared with existing models, the model proposed in this paper can well simulate the runoff and infiltration rate, and the measured values are in good agreement with the simulated ones. However, during storm periods, the simulated infiltration rates are far less than the measured ones. A possible reason is that rock fragments in soils may cause the formation of fast flow paths in the earth-rock interface, which is neglected in the present model. This model needs to be further refined and improved to consider the priority flow paths inside the soil layers and bedrock layers in earth-rock mountain regions.