Human population growth and consequent spatial distribution of human society requires application of new technologies for safety issues. Risk assessment is necessary to mitigate harmful consequences of possible devastating earthquakes on the human societies. A novel method is presented in this study to be applied as a criterion for the assessment. The criterion has been used to make a seismic zonation of Bushehr Province before the catastrophic earthquake of April 9, 2013, happened in the area. The objective of this study is to explore the factors effective in seismic zonation. Fault locations and seismic records have been used as the material. Four criteria of distance to faults, distance to seismic points, interpolation of earthquake magnitudes, and interpolation of the earthquake dates have been analyzed using a methodology to classify the province in terms of earthquake susceptibility. The results indicate that the devised method of date frequency interpolation have been able to find accurately the areas prone to strong earthquakes. This is concluded that the criterion can be recommended for use in multi-layers analysis of site selection studies.