In this study, we used the program for seismic hazard Bayesian estimate which was elaborated by Alexey Lyubushin. Our study is the next in the sequence of applications of this software to seismic hazard assessment in different regions of the world. However, earthquake hazard parameters of maximum regional magnitude (), beta value and seismic activity rate or intensity (lambda) and their uncertainties for the 15 different source regions in Iranian Plateau have been evaluated with the help of a complete and homogeneous earthquake catalogue during the period 1900-2014 with a parts per thousand yen4.0. The estimated values varies between 6.25 and 8.37. Lowest value is observed in the Zagros foredeep whereas highest value is observed in the Makran. Also, it is observed that there is a strong relationship between the estimated maximum earthquake magnitudes estimated by Bayesian approach and maximum observed magnitudes. Moreover, in this study, quantiles of functions of distributions of true and apparent magnitudes for future time intervals of 5, 10, 20, 50 and 100 years are calculated with confidence limits for probability levels of 50, 70 and 90 % in 15 different source regions. Based on computed earthquake hazard parameters, the prerequisite guides to the earthquake estimation of the parameters referred to as the most seismically active regions of Iranian Plateau. The Makran and East Iran show earthquake magnitude greater than 8.0 in next 100-years with 90 % probability level as compared to other regions, which declares that these regions are more susceptible to occurrence of large earthquakes. The outcomes which obtained in the study may have useful implications in the probabilistic seismic hazard studies of Iranian Plateau.