Abstract: Sliding snow loads are an important component of snow loading on roofs. A simulation method for sliding snow loads is developed in this paper. Firstly, based on previously developed mass and energy balance models, a building roof snowmelt model is developed, which focuses on the features of the snowpack. Based on this model, it is proposed that the sufficient condition for roof snow sliding is that the liquid water in the snow exceeds the maximum water capacity of snow. Using the method for calculating sliding snow load proposed in the paper, simulations of the sliding snow loads on roofs in several representative areas in China are performed, and the influences from climate features and shielding effects of neighboring buildings are analyzed. At the same time the contributions of a variety of energies to snow sliding are presented quantitatively.