Abstarct: Drilling is an expensive and necessary operation for the exploration and exploitation of hydrocarbon materials. One of the most important goals in drilling operations is to achieve higher drilling speeds at lower costs along with maintaining safety. In drilling operations, the time and efficiency of operations are of great importance as factors directly related to drilling costs. One of the criteria for the efficiency of drilling operations is the rate of drill bit penetration. Estimating this parameter and knowing it when planning for a well drill can help to more accurately assess the drilling time and estimate its cost. Also, reasonable knowledge of the physical and mechanical properties of the rock and the proper selection of drilling operations parameters will greatly help to reduce the cost of drilling and production.in this study, to verify the parameters affecting the penetration Rate, first the scientific articles and papers were studied and the mast important parameters were divided to tow controllable factors (operational) and incontrollable factors (environmental). Optaining the model can achieve the relation between this parameters and penetration rate always has been specially important. However, mathematical model presented in this regard, mostly emphasis on controllable and operational parameters. The complexity of the bit and stone confrontation as well as the simultaneous influence of factors affecting the penetration rate have caused the usual methods to be completely unable to analyze and predict the penetration rate. The main reason for this can be attributed to the multiple factors affecting the penetration rate and, on the other hand, the interaction between these factors.To overcome this problem, the Rock Engineering Systems (RES) method has been used. In order to verify the parameters affecting the penetration Rate, from information One of the wells of Azadegan oilfield has been used. To this purpose, firstly, 11 parameters affecting the penetration rate have been identified. Secondly, Utilizing the rock engineering system (RES) method, Penetration index has been introduced. This index has been calculated for four different depths of the well. The results show that in the studied field, the depths of 2728 and 3574 m, have the highest and lowest penetration index, respectively. Also, Among the parameters affecting the penetration Rate, porosity was identified as the most effective factor in penetration rate.