Abstract: Using the data of snow grains line from Glacier Inventory of the Tianshan Mountains, group 1051, by processing the data, incorporating the scattered samples into regular grip distribution, and further interpolation as to promote the fitting degree, we prepared the trend surfate map of snow grains line which coincides with the practical data, from the map it may be seen several features of snow grains line of the Tianshan Mountains：①Ridge line of the trend surface stretches along the direction of latitude. ②Longitudinal variration of altitude greater than that of latitudinal direction. ③Maximum longitudinal variation rate occurs at the Hantengeli Mountain. And. ④highest point of the trend surface locates at south slope of the Tuomuer Peak and the lowest in the upper reaches of Gongnaisi River Valley.