Abstarct: seismic waves due to earthquake when passing through different soil laxyers cause a lot of changes which can be found in the heterogeneity and spatial variability of soil parameters affecting seismic response of the ground. Therefore, considering the effects of heterogeneity and uncertainty in soil parameters such as shear modulus is an important step in dynamic analysis of ground response. for this purpose , by using random field theory in combination with monte carlo simulation, the effect of 2D spatial random variations of soil parameters on the seismic characteristics of soil profile in this research is investigated as a the amplification factor and acceleration response spectrum . in this study, a soil profile with constant length and thickness and random distribution of shear modulus parameter is modeled using FLAC 2D computer program under near field and far field earthquakes and using Monte Carlo simulation method, the average acceleration amplification factor and the acceleration response spectrum of Soil profile surface is calculated for all the random distribution states of the shear modulus (variation coefficient and different correlation lengths) in the soil. the results of the dynamic analysis of soil profile investigated in this thesis show that by increasing the coefficient of variation soil shear modulus and consequently increase of heterogeneity in soil profile , the average peak ground acceleration amplification factor as well as the acceleration response spectrum of Soil profile surface decrease. in addition, a comparison of the results of deterministic analyses with a random analyses performed in this research shows that ignoring the spatial variations of the soil shear modulus in deterministic analyses will lead to a overestimation of the peak ground acceleration amplification factor and the acceleration response spectrum of Soil profile surface.