The method of the analysis of the base Gummel number of the BJT(Bipolar Junction Transistor) for integrated circuits based upon the semiconductor physics is proposed and the method of calculating the doping profile of the base region using process conditions is presented. The transistor saturation current obtained from the proposed method of NPN BJT using 20V and 30V process shows an averaged relative error of 6.7% compared with the measured data and the transistor saturation current of PNP BJT shows an averaged relative error of 9.2% compared with the measured data