This paper proposes a new top-down technology mapping algorithm for minimizing the chip area and the path delay time of lookup table-based field programmable gate array(FPGA). First, we present the decomposition and factoring algorithm using common subexpre ssion which minimizes the number of basic logic blocks and levels instead of the number of literals. Secondly, we propose a cube packing algorithm considering the decomposition of gates which exceed m-input lookup table. Previous approaches perform the cube packing and the gate decomposition independently, and it causes to increase the number of basic logic blocks. Lastly, the efficiency.