Investigation of geotechnical vulnerability (liquefaction) and Zonation of the southern region of the Caspian Sea is my most important aim in terms of destructive earthquakes hazard potential. Past geologic events on the south coast of Caspian Sea indicates that destructive earthquakes lead to the death of numbers in this area. Remained evidence of seismic events happening indicates extensive landslides, liquefaction and soil subsidence in the residential and even natural area. Therefore, in this study determination of geotechnical vulnerability (liquefaction) intensity in southern coast of Caspian Sea against natural forces resulting from earthquakes and coastal construction via geographical information system environment (GIS) is considered as the research most important purposes. Therefore, seismic and consequence natural phenomena hazards potential are high in Southern Caspian region. The results of this study indicate that in terms of performance of instability factors such as: storm waves, sedimentary material subsidence and slide, coastal sand liquefaction, the southern part of the Caspian Sea coastal areas and sea bed sections are so vulnerable.  So my aim of this study at first is to illustrate the variety of methodologies currently in use for preparation of seismic hazard maps and to evaluate basic principles of zonation for different purposes and at different scales. Guidelines and recommendations for seismic microzonation should be incorporated into seismic regulations. Indeed, by its results susceptible of risk area are determined and high risks areas are identified in terms of occurrence of geotechnical processes such as liquefaction by this recommendations many researchers apply  this methods for seismic-geotechnical hazard zonation in three grade.