A dynamic model of the formation of winter hardiness of winter wheat plants during the autumn period of vegetation, which describes the growth processes, plant development and the passing of the two phases of the autumnal hardening under the effect of agrometeo-rological conditions in autumn, was developed. Effects of intensity of photosynthetically active radiation (PAR), sunlight levels, air temperature and soil moisture on the increment of reserves of photosynthesis products and soluble carbohydrates in winter wheat plants are described. The results of numerical experiments showed a significant influence of intensity of sunlight levels and air temperature on the passing of two phases of hardening during autumnal period of vegetation of winter wheat plants.