Seismic hazard assessment like many other issues in seismology is a complicated problem, which is due to a variety of parameters affecting the occurrence of an earthquake. Uncertainty, which is a result of vagueness and incompleteness of the data, should be considered in a rational way. Using fuzzy method makes it possible to allow for uncertainties to be considered. Fuzzy inference system, is used since the study based on uncertainty estimation of seismic hazard for the region Qom, is done. First, the input parameters required for Seismic hazard assessment is fuzzified by fuzzification (in Matlab fuzzy tool-box) and the membership functions are used to set the degree of membership. The inference engine produces fuzzified sets using the output from the fuzzification stage and the rule base engine. The fuzzified sets are then defuzzified using the center of the area. Eventually, using a set of attained coordinates for the Holy Shrine (Masoumeh) a deterministic estimation of seismic hazard is made using both the usual deterministic approaches and the Mamdani fuzzy Inference System. Our results show a peak ground acceleration value of 0.43g using fuzzy inference system. پرونده مقاله