In this study,by the considering twenty - one ro dent species that ranges in Zanjan provience,it was determinet that of them nine species might be occured in grain fields.Of roden species Microtus socialis ,Microthus arvalis,Meriones tristram ,Meriones vinogrodovi,and Ellobius lutescens mightprimarily harmfully effect on cultivated grain fields.It was also revealed by the providing some knowledge abut species mentioned that deep ploughing in width of 0.5-1 meters of field edges is effectable method for taking measures against to their harmful effects.