Abstarct: The catchment area of Bidvaz Esfrain River is one of the important karst areas in North Khorasan province, and no comprehensive study has been done regarding the development of karst in this area. In the studied area, the thick laxyered and massive limestones of the Mazdaran and Tirgan formations form the karst aquifers of the area. In order to investigate the development of karst in the target area, in addition to field visits and geological and geomorphological investigation of the area, a number of six relatively large karst springs in the area have been hydrogeologically and hydrogeochemically evaluated. baxsed on the field surveys, it was observed that in the upstream part of the catchment basin of Bidovaz River, outcrops of Chaman-Bid Formation can be seen under the Mazdooran Formation, which is not mentioned in the geological map of Shirvan 1 to 100,000. It was also observed that in the karst basin of Bidovaz river, there are karst effects including karsts, dissolution holes and dry karst valleys, but there are no significant morphological effects such as karst plateau, sinkhole, blocked pit and karst well, which indicate the development of karst. There is little karst in the region. According to the statistics of 1397-1398, 97 karst springs have been observed in the catchment basin of Bidovaz river, most of them have low water flow, which confirms the small development of karst in the region. Examining the hydrograph and descent curve of six selected karst springs showed that the coefficient of change of irrigation in all these springs is relatively low and in all of them the descent curve has a slope, the value of the yield coefficient is less than 0.005, which indicates the dominance of such characteristics. The flow system of Afshan is in the karst area of the catchment basin of Bidovaz Esfrain river. In addition, the electrical conductivity variation coefficient in the selected karst springs is less than 5%, which confirms the dominance of the seepage flow in the aquifer that supplies water to these springs.