The majority of petroleum reservoirs in Iran are in fractured formations. Modeling fractured reservoirs, for comprehensive study and development scenarios, always faced with difficulties and complexities in comparisonwith conventional that called the most complicated geologic structures. As the matter of fact proper and reliable investigation of fractures properties as the main agent of fluid flow and also storage in this type of rocks, seemsessential. Fracture geometric modeling methods as one of primary steps of reservoir modeling, varies from former continuum to recent discrete models and from deterministic to stochastic approaches. In the following study, a new Global Optimization method –i.e. Simulated Annealing is introduced developed and related PC Spread Sheet addins is designed. At last the code rendered with Illam Formation’s real data and fractures network presented

discrete fracture network, simulated annealing, optimization based modeling,stochastic modeling