A number of computer resources, such as CPUs and storages, can be connected over networks to construct a huge virtual computing environment using grid technologies. Our project "g-Drug Discovery" aims to develop a platform for drug discovery using grid technologies, on which various analysis and calculations are conducted, such as molecular mechanics method, replica exchange method, docking with proteins, molecular orbital method, and 3-dimensional quantitative structure activity relationship. For this aim we have specified a markup language for drug discovery (DrugML) and constructed database system. In this note we report some results of a ligand-receptor docking simulation, which is calculated on this platform using a grid RPC system "OmniRPC" and virtual screening software "Xsi" (ku-su-shi). We assume only 2-dimensional structure of ligand and 3-dimensional structure of receptor, and reproduce the complex of these molecules.