Abstract: The waterstorage variations of the Qilian Mountains were recovered using GRACE monthly gravity field data，with a 1°×1°spatial resolution and an 8-year time series length （2003-2010）. These GRACE data were smoothed by Gaussian filter before application. Meanwhile，the spatial-temporal variations of waterstorage change in the Qilian Mountains were analyzed using time trend analysis method，combining with monthly precipitation data of 35 regional meteorological stations. The results show that，on the spatial distribution，the amount of waterstorage of the Qilian Mountains is different significantly，higher in the west and the south，lower in the east and the north; as to time trend，the changes of waterstorage have obviously seasonal variation，same to the precipitation，and their changing processes keep consistent. The annual distribution of average water storage in the Qilian Mountains turns to be increasing except for Dec. The changing trends are shown as positive increase between Jan. and Nov.，with a maximum value of 47.8 mm/a in July，and negative growth in December，-2.5 mm/a. In general，the amount of waterstorage in the Qilian Mountains was increased year by year during study time period; the average growth rate is 0.72 mm/mon，increased about 13.6×10⁸ m³ totally. The main reasons are as follows：（1） permafrost degradation caused by climate warming，which makes the active layer thicker and water volume increase；（2） water resources conservation forest construction is increased yearly，which can improve water conservation function in the mountain area.

Key words: GRACE satellite, waterstorage change, temporal-spatial distribution, precipitation, the Qilian Mountains