Abstarct: Land subsidence and earth fissuring are natural important hazards which is involved with most of plains in Iran and leads to damages of urban area, roads, bridges, power transmission lines, agriculture lands, wells and piezometers. In this study in the one hand the occurrences pattern of regional subsidence phenomenon in the Semnan plain and also the zoning of this region in terms of the susceptibly of land subsidence have been discussed and in the other hand, mechanism of earth fissuring and its hazard and in the south and south-east of the plain was evaluated. For this reason at the first step data of 18 piezometers for 24 years period (May 1993-2017) were used to provide iso-potential lines of drawdown groundwater table and unite hydrograph of the plain. Furthermore, for the determination of type and thickness of the subsurface laxyers some data including piezoelectric log, geoelectric sounding and geological map were used. Then, using the drawdown groundwater level map and the subsurface laxyers conditions map, a subsidence susceptibility map of the Semnan plain was prepared. For evaluation of earth fissuring several geological and geotechnical approaches were used, including comprehensive field investigations, soil disturbed and undisturbed sampling, and laboratory assessments (particle size distribution, Atterberg limits, double hydrometer, pinhole, Cramp, double consolidation tests and etc). Finally, hazard and risk zonation maps of the study area were prepared baxsed on the obtained results.The results showed that during the period of 1993-2018 continuous extraction of groundwater caused a drop of 18.9 meters of groundwater level and provided conditions for consolidation of clayey laxyers and land subsidence. The subsidence hazard zonation map indicates that the area with a high potential of subsidence in this plain is located in the northeastern part of the plain and in the south-southwest of the Semnan industrial park. Furthermore, results showed that a combination of the presence of problematic (collapsible and dispersive) soils and various human actives such as construction of road and railway contributed to fissure formation and expansion in the study area. In fact, gully erosion due to these two parameters was distinguished as the main mechanism of earth fissuring. This study results indicated that earth fissuring is an ongoing problem in the study area that endangers the safety of railway, down part of Semnan airport and Alla village.