Abstarct: Global climate change and overpopulation have led to an increase in groundwater demand. The risk of land subsidence due to groundwater pumping and water depletion is happening on various scales and it is one of the environmental hazards that threaten the communities. Subsidence means the collapse of the earth with a slight horizontal displacement vector. Semalghan plain is one of the agricultural plains in North Khorasan province. baxsed on the regional water authority organization of North khorasan information, most groundwater resources are extracted by deep well from this plain and it has a critical situation. Radar interference techniques have attracted the attention of researchers in recent years due to their acceptable accuracy and speed of monitoring. In this study, to investigate land subsidence due to groundwater drop in Semalghan plain using radar differential interferometry technique from ascending and descending data of Sentinel-1 satellite, 35 interferometers in the range of 2014-2020 have been processed and analyzed. A comparison of ascending and descending data processing results showed the same pattern of land displacement Groundwater level and depletion maps have been produced using GIS and their relationship with subsidence has been investigated. Also, the relationship between tectonic activities, plain geological conditions, and vegetation of the region with subsidence was studied. The result maps shown a direct relationship between water table head and subsidence. Maximum subsidence in this plain in 2019 is equal to 34 cm and a minimum of 18 cm in 2015 and 2018 is estimated. The maximum subsidence rate in the Semalghan plain was 12 cm per year and 0.32 mm per day. The average annual groundwater level drop is estimated to be 0.47 meters. Studies have shown that subsidence has occurred in areas with more fine coarse grained soil. Finally, according to the land behavior in the studying area, some suggestions have been proposed to control the subsidence.