Exact and systematic planning to make, hold, and increase employees' motivation is from important methods for increasing organizational productivity. This program needs a full-scale ecamination and to perioritize effective factors to improve motivation and human force productivity. Therefore, in this article, the factors affecting employees' motivation are identified and classified by fuzzy network analysis model. The research results show that there is a positive and significant relationship among reward system, motivation factors, and human resources productivity. Also, among the options of reward system, the factors of internal (inherent) reward, non-financial external reward, and financial external reward had the most impact on increament of motivation and productivity factors. The research results of priotitization of motivation factors in Fars Oil Distribution Company show that sense of fair able income according to the task, fulfillment of performance evaluation, providing the opportunity of progress for all employees, coordination between job specifications and employees' abilities, and a manager competency are very critical for improving the organization productivity.