Based on high latitude and ground observations of 70 heavy snowstorm weather processes from September to May during 1961
－ 2010 in Altay region，the climatical characteristics of snowstorm weather occurring in Altay were analyzed by using statistical and climatology
methods． Results show that before the 1990s，the heavy snowstorm weather occurred less under the background of cold winter
climate，but after the 1990s，when it became warmer in winter，snowstorm weather occurred more． It occurred less frequently in spring
and autumn，and appeared mostly in November and December mainly in northern and eastern part of Altay． On 500 hPa geopotential
height field，heavy snowstorm appeared mainly under the macro － scale circulation situation with two ridges and a trough，and vortex
was the synoptic scale impacting system of snowstorm． Altay was in the bottom of the strong frontal zone． There was low trough over
middle and low latitudes of the Black Sea and the Caspian Sea region and constantly split shortwaves moving to northeast and converged
with the strong frontal zone at the bottom of vortex，which provided favorable atmospheric circulation background for heavy snowfall． On
the level of 700 hPa，there was stronger west ( or southwest) wind convergence over Tacheng，Kelamayi and Aletai region． On the level
of 850 hPa，the shear line formed between Tacheng，Kelamayi and Aletai region was the trigger condition of the heavy snowstorm． On
ground，heavy snowstorm occurred in the back of Mongolia high pressure．

Based on meteorological data including monthly maximum snow depth, snow cover days and snowfall days, the beginning and ending snowfall date, and winter average temperature, the highest and the lowest temperature, precipitation (1961-2008) obtained from 7 weather stations in Altay region, the snow cover variation was analyzed using linear trend, Mann-kendall test and R/S analytical methods.The results indicated that winter mean temperature presented significantly increasing trend, especially for the minimum temperature, and precipitation also increased. Snowfall and snow cover occurred early in September or October and ended in next April or May in most areas of Altay.The yearly mean maximum snow depth and snow cover days presented a single peak variation, and the maximum snow cover depth was in Altay station, the minimum value is in Fuhai station, snow cover days was miniimum in Fuhai and maximum in Jimunai, while snowfall days decreased from west to east. The maximum snow depth increased obviously, and the variation of snow cover and snowfall days were not so obvious, but some difference existed in spatial distribution. The snow cover days and the snowfall days decreased obviously. The abrupt change test indicated that in regional mean, the maximum snow depth changed abruptly in about 1983, which was consistent with winter precipitation change. R/S analysis indicated that the maximum snow depth, snow cover days and snowfall days would be anti-persistence in future, and the anti-persistence characteristic of mean snowfall days, the maximum snow depth in Fuhai, snow cover days in Jimunai, snowfall days in Buerjin would be strongest relatively.