Abstarct: Generally, there is no clear and precise relationship between porosity and permeability values. The relationship between porosity and permeability is qualitative and we do not have a general quantitative relationship between them can be valid in all cases. One of the useful methods for classifying reservoir rocks and separating production and non-productive zones is the definition of reservoir zones baxsed on hydraulic flow units using the concept of cluster analysis, which has a new perspective on the definition of rock type and reservoir zoning. In this way, the disadvantages of common geological and petrophysical zoning are eliminated. determination of hydraulic flow units is a suitable method for studying and evaluating the porosity-permeability relationship in hydrocarbon reservoirs. In this study, for the purpose of providing the porosity-permeability relationship, hydraulic flow units were first determined in a well of the study field using the methods of flow zone index, electrical facies, histogram, discontinuous rock type, K-means clustering, hierarchical clustering and reservoir quality index. In order to determine the flow units as well as to investigate the porosity-permeability relationship, the Excel software is used and a computer program is made in MATLAB. In addition, the Geolog software is used to determine the flow units by utilizing the electrofacies. The results show different numbers of hydraulic flow units using the above-mentioned methods. However, in general, for the simplicity of the interpretation of the results, 7 hydraulic flow units were considered. The results of the study of porosity-permeability relationship in the studied well showed a high correlation coefficient between porosity and permeability values using in the methods of flow-zone index, DRT, K-means clustering and hierarchical clustering. However, the determination of hydraulic flow units using the method of electric facies is possible with the help of petrophysical logs, even if porosity and permeability data are not available. In the final stage of this study, porosity and permeability have been modeled using geostatistical methods by the Petrel software in the reservoir being studied. The results indicate that porosity and permeability throughout the studied reservoir do not follow a particular pattern and change from zone to zone. The relationship between porosity and permeability in all reservoir zones is relatively weak. The average values of porosity and permeability throughout the reservoir are 7% and 24.5% millidarcy, respectively.