Abstract: Based on the data of gradient observation in the mountain areas during April 1983—March 1986 and taking into account the matched relationship among sunlight, heat and water resources, an estimation model is established for the climatic productivities of crops in the different elevations, slope orientations and mountain areas. In the model, meteorological elements of temperature, precipitation and sunshine in the mountain are amended, and the climatic productivities of rice, corn and winter wheat are estimated. The results show that in generally, in the hilly and mountainous areas in the east of subtropics of China, climatic productivities of single cropping of rice, double cropping of rice and summer corn in the south of slope orientation are higher than in the north, and those in the west of slope orientation are higher than in the east. Climatic productivities of spring corn and winter wheat in the north slope are higher than in the south, and those in the east slope are higher than in the west. Climatic productivity of late double cropping of rice is higher than early rice, that of summer corn is higher than spring corn (except for the Shen–Nong Jia mountain). It is necessary to point out that the high output of rice in some typical sites can come to over 60 percent of climatic productivity, while the outputs of corn and winter wheat are only about 30—50 percent of their climatic productivities. It is shown that the potential of agroclimatic resources exploitable in the mountain areas is still rather high. The quantitative results in this paper would be useful for the efficient exploitation of climatic resources, the rational adjustment of agricultural distribution and the enhancement of yield per unit area in mountain areas.