In agricultural activities, multiple inputs and sources are use. The main objectives of farm managers and planners were to optimizing the resources usage and inputs for determining appropriate cropping pattern. Hamedan province and Bahar county has high potential for agricultural productions. The main purpose of research was to investigate optimal cropping pattern for Bahar county for crop years of 2013-2014. For the mentioned aim, mathematical planning and simulation of cropping products on the basis of water input. Data were analyzed by Lingo10 software in mathematical model. In the study, feasibility of efficiency maximization and investment cost, water usage, chemical matters minimization were analyzed according to land limitation and water availability. Results show that for the purpose of mentioned aim planning efficiency of product were increased: 8.44 percent, investment cost 2.94percent, chemical manure usage 3.05, chemical toxins usage 0.88 but water usage 1.99 percent decreased. It can be expected that findings will contribute to agricultural related organizations and planners.