Abstarct: By comparing countries in temperate regions with Iran that has dry and semi-arid climatic conditions, water scarcity is one of the most important deterrent factors in the development of the country. As a result, Proper utilization of existing water resources especially groundwater resources has always been one of the most important and reliable water sources in arid and semi-arid regions and the extraction of water from these areas than the other climates is of particular importance. The purpose of this thesis, Estimated annual changes in groundwaters level in Iran by using GRACE satellite datas and three outputs of the GLDAS model are Snow Water Equivalent, Soil Moisture and Total Canopy Water Storage, During August 2002 to August 2016. To eliminate the existing error in GRACE satellite datas, The Wavelet and Gaussian filter methods was used. And finally, Validation of groundwater level changes was done by observation wells datas at the provinces of Razavi Khorasan, and South Khorasan. The results of the decline in groundwaters level in the country during 2002 to 2016 and also better precision of Wavelet method compared to Gaussian filter showed.