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In this research a proposed methodology is improved to identify how the stresses increase between two Earthquakes in Kuhbanan fault zone (Iran). Using the Mohr circles of the Earthquake we could calculate the main stress (σ<sub>1</sub>), hydrostatic stress, normal and shear stresses and the initial and final Coulomb stresses for all individual Earthquakes. For the relation of the whole fault we need the initial and the final Coulomb stress as well as the time during which the stress reaches from initial value to the final Coulomb failure value. The initial Coulomb stress is chosen as the least value, to be 30 megapascal. For the final Coulomb stress we used the average final Coulomb stress of all Earthquakes and for the time between this two initial and final stress we use the average time between Earthquake that is 3377 days. Using the Coulomb stresses at selected times, one can see how the stress increase with time between Earthquakes. The best fit of points of stress versus time is a polynomial relation. The model will help to estimate the stress accumulation with time until the next event, this means one can estimate the approaching time to the next main shock.