Based on bipolar junction transistor (BJT) modeling the theoretical analysis of biasing effect on improvement of linearity and efficiency of RF linear power amplifier (LPA) are introduced, according to these analysis and by using matlab curve fitting toolbox an analytical model for improvement of linearity and efficiency of RF linear power amplifiers (PAs) is introduced. This model simplifies the traditionally complicated methods of analysis of RF PA. According to a change of the DC bias as a function of the AC input signal of RF linear PA the linearity and efficiency can be improved.