The main objective of this study refers to zone Arak city by using geomorphological parameters of the fuzzy logic model. In order to fulfil these objectives, 10 parameters such as effective height, the distance from fault, the distance from the main channel, the distance from sub-channel, distance out of the way of communication, slope percent, distance from settlements, topography type, land erosion and seismic vulnerability in the form of raster and vector maps were prepared. Each raster layer was defined based on research studies and expert's opinion. But being in a range of vector layers 0 and 1 did not need to be defined. After applying the functions, operations, multiplication, addition and different values of gamma phase were also performed on the layers. So, ARC GIS 9.3 and ERDAS 9.1 software were used. Since, comparison analysis has been done between the suitable arenas to real situation of city according to the critical arenas and suitable arenas of the gammas quantities. Based on finding, the fuzzy gammas have been in match with the most suitable lands of the town. The results indicated that two stations in the West and the East of County seemed suitable for the future development of Arak, but the north and northeast arena of city were the first priority at present time. At last, the final map was classified to 5 classes: very low portion 2189, low proportion 389, medium proportion 593, high proportion 552 and very high proportion 381 with a great square kilometers were defined, respectively.