At present the processing power of the digital electronic chip is enormous and that has been possible because of the continuous improvement of the design methodology and fabrication technology. So, the data processing capability of the chip is increased significantly. Data processing in the electronic chip means the arithmetic operation on that data. For that reason, ALU is present in any processor. Full adder is one of the critical components of arithmetic unit. Improvement of the full adder is necessary for improving the computational performance of a chip. In order to design an efficient full adder, designer should choose an appropriate logic style. In this research, two new model of full-adder circuits are designed and analyzed using Pass Transistor logic in order to reduce power consumption and increase operational speed. The first proposed adder consists of 8 transistors and the second one consists of 10 transistors. LTSPICE is employed for simulating the proposed circuits using16nm low power high-k strained silicon transistor model. The overall performance of the proposed adder circuits and comparative results demonstrate the superiority of the proposed model.