Abstarct: The study area is located in Semnan province, Miami and kalpoush city. This region is part of the structural and sedimentary unit of the Alborz (East Alborz) geological perspective in Iran And is located 110 kilometers northeast of Miami. The studies carried out on field observations and data from seismographic sites have been used to investigate the structural and seismicity of the region. The main faults of the area are the Cheshme-Nik and Nardin faults, respectively, with a length of 79 and 32 km, and the trend of Northeast-Southwest, has exposed significant effects and exposed on rock units. Given the field data taken out of the exposed areas, the mechanism of these two faults is inversely. The quaternary movements of the Cheshme-Nik fault can be easily observed on quaternary deposits. Therefore, the Cheshme-nik fault is a quaternary inverse fault. Using seismic data (2018-1958) in Cheshmeynik area and plotting these data on the map of the studied area, it was determined that the seismic density along the fault was determined at the two ends of the seismic density It is more than the middle part, in the southwest of the fault, due to the existence of branching fissures branching and connected at the end of the fault terminus, the density is greater than the rest of the length of the fault.