The current mode circuits have now developed into a solid competitor for the voltage mode circuits. Free algebraic summation, simplicity of the design and accessible approach to the desired speed by adjusting the current and several other ascendancies, have induced the current circuits to acquire a particular position in the logic styles. A novel mixed mode current and dynamic voltage CMOS 1-bit full adder cell is presented. In this new design, by combination of voltage and current mode circuits and adopting the advantage of each circuit in the finest way, the authors obtain the highest possible speed. The results are validated through HSPICE Simulation with 0.18 um and 1.8v, Vdd.