Abstract: An experiment was conducted to figure out the reasonable colony structure of “Chuanyu 117”, which was designed with randomized block in five different densities (6×10⁴, 9×10⁴, 12×10⁴, 15×10⁴ and 18×10⁴ plants·hm^-2), so as to make full use of light and temperature to increase potato yield and efficiency in Sichuan Basin. Compared with spring potato, autumn potato had higher plant height, smaller stem diameter and less branch number, and its leaf area declined more slowly at the tuber bulking stage. The dry matter accumulation and tuber dry matter allocation ratio of spring potato were higher than those of the autumn potato, so spring potato yield was significantly higher than that of autumn potato, with an average increase of 88.5% in this experiment. With the increase of density, the leaf area and total dry matter accumulation of spring potato increased and then decreased, and the total dry matter accumulation arrived at a peak point with a density of 16.20×10⁴ plants·hm^-2. Meanwhile, autumn potato leaf area and total dry matter accumulation increased with the density increase, and the maximum total dry matter accumulation was at the density of 18×10⁴ plants·hm^-2. In the range of density test, the yield of spring potato showed a convex quadratic relationship with density and reached the maximum value at the density of 15.75×10⁴ plants·hm^-2. The yield of autumn potato was positively linearly related with density, and the maximum value was at the density of 18×10⁴ plants·hm^-2. The density obviously affected the single tuber weight of spring potato, while it mostly affected the tuber number per plant of autumn potato. With the density increase, the seed costs increased but the marketable tuber percentage decreased, thus the net income changed. So, the most profitable densities in spring and autumn were 12×10⁴ and 15×10⁴ plants·hm^-2, respectively.

Key words: development pattern, counteracting snow movement model., Caragana microphylla, shrub characteristics, snow morphology