Abstarct: The Mojen plain is an important agricultural and horticultural area in the Shahrood area. The aim of this study is to evaluate the contamination of agricultural soils and groundwater resources of Mojen plain by heavy mextal, nitrate and phosphate and in order to assess the impacts of agricultural activities on soil and groundwater contamination. For this purpose, 12 topsoil samples (0-20 cm depth) and 2 subsoil samples (20-40 and 40-60 cm depths) were collected from the farms and gardens. Also one soil sample from a barren site was taken as local background sample. 18 groundwater samples were also taken from the agricultural wells. Physic-chemical properties (pH, organic matter content, calcium¬¬ carbonat content and texture) and total concentration of heavy mextals in soil samples were determined using standard methods. In water samples the chemical parameters (e.g. pH, EC), nitrate, phosphate and heavy mextal concentration were analyzed. The obtained data were interpreted using comparison with standard values, calculation of geochemical indices (i.e. EF, Igeo, CF, Cd, PLI, RI) and statistical approaches (correlation coefficients, cluster analysis, PCA). The results showed that in the studied soil samples, the total concentration of Cd, As, Cu, Zn, Ni, Cr and Mn are higher than local background sample. Also the concentration of these elements (except As) are higher in topsoil than subsoil. The total concentration of Sb, Fe, Al, Sc, Mo and Co are approximately equal or less than local background sample, the concentration of these elements are higher in subsoil than topsoil too. The calculated geochemical indices showd that the studied soils are contaminated with Cd, As, P, Sb and Zn. The contents of As and Cr in water samples were higher than WHO standards for drinking usages, but Ni, Fe, Al, Pb, Zn, Cu and Cd concentration in waters were lower than this standard With increasing the wells depth, the concentration of all studied elements (except Ni and Co) are reduced that indicates the anthropogenic origin for these elements. The higher content of nitrate and phosphate in shallow wells compared with deeper ones, confirm this idea. On the baxse of the calculated qualitative indices, the water resources of the area studied area are contaminated and are not suitable for drinking. The obtained results of this study indicate that the agricultural activities and widespread useage of various fertilizers, pesticides and agrochemicals in farms and gardens of Mojen plain are the main important sources of mextal contamination of soil and water resources.