Abstract: Soil testing is a general soil productivity evaluation program that helps farmers touse chemical fertilizers wisely. The purpose of this study was to investigate the effective factors on adoption of soil testing for fertilizing farms. The research instrument was astructural questionnaire with close ended questions which confirmed its validity andreliability. The target population included all farmers in the Shahreza township of Esfihan Province (N = 9,825). Among of them, 215 persons were chosen by using the Cochran formula through stratified sampling as the statistical sample and finally 195 questionnaires were analyzed (n = 195). There was a significant difference between the personal, farming and educational characteristics of adopters and non-adopters of soil testing. The result of discriminate analysis showed that knowledge about soil sampling principles, the amount of extensional contacts about soil testing and educational level were identified as the most discriminative factors (74.40% of population) affecting the adoption of soil testing.