Abstract: Solid precipitation in existing glacial area on northern slope of Bogda is absolutely dominant. About 77 percent of the annual precipitation is concentrated in months May-September, commensurable to the total accumulation amount. From the record of Tianchi from 1980 to 1981, precipitation in the glacier area is found to be more than 600 mm. Because of differences in solar radiation with slope facing, the source of water vapour and other factors, glacial accumulation is distinctly different according to slope facing. Data from snow pits do not perfectly show the regularity of the increase in net accumutation with the rise of elevation. The net accumulation amount (water equivalent) of glacier No.4 was 4.36×10⁵ m³ during 1980-1981, and the mean depth of net accumulation (water equilalent) was 147.3 mm.According to mean annual temperature data for many years the period of glacial ablation in this region is from May to September, and the strongest from June to August, during which glacial ablation is closely correlated with temperature and elevation. Because a large part of precipitation is concentrated in ablation period and new snow has a stronger reflection rate, the strength of net ablation is influenced to a certain extent. During serveying, the net ablation amount (water equivalent) of Glacier No.4 was 4.127×10⁵ m³ and the mean depth of net ablation is 139 mm, the net ablation gradient being 1.35 mm/m.The mass balance of glacier No.4 was negative during 1980-1981. The level of the mass balance was not high (only 600 mm). It is consistent with Laohuogou glacier, in Qi Lian Shan (641 mm) and with glacier No.l at the head of Urumqi river, Tian Shan (685 mm), but much less than Guxiang glacier, Pomi county Tibet (2678 mm).