According to the Boltzmann code for the free electrons and calculation of kinetic processes, the major chemical species and kinetic processes in XeCl discharge laser were chosen for a simple kinetic model. The relationship between the fluorescence intensity and total gas pressure was calculated at different gas mixture and discharge current densities by using this simple model. These results are in good agreement with the experimental results of the X-ray preionized avalanche self sustained discharge pumped XeCI laser. This model can also explain the laser output characteristics for different gas mixtures and total gas pressures.