In this paper, we proposed the effective 3D graphics processor that has real-time 3D graphics acceleration for a mobile system. We designed 96bit SIMD(Single Instruction Multiple Data) architecture that be able to process 4M polygons/sec. The 3D geometry processor was based on a floating point arithmetic unit. The geometry processor was implemented by 160K gate area in a Xilinx-Vertex2 FPGA, and measured the performance using actual 3D graphics test bench at 80MHz.