Inorder tosimulate large scale biological models witha reconfigurable FPGA-based biochemical simulator system, reduction ofrequired resources areessential. Thispaper proposes amethodwhichcombines commontermsinrate lawfunctions appeared inbiochemical models andgenerates ashared hardware module usedfornumerical integration. In this approach, twofunctions arecombined inatree structure level, followed bypipeline scheduling andarithmetic modulebinding. Theevaluation result reveals that this approach reduces hardware resources by31.4% onaverage atthecost of14.4% throughput degradation.