As e‐commerce in the Internet environment is settled as a main pattern of transactions among businesses, there are increasing demands for standardized B2B business models to break away from closed structure and enhance outsourcing capabilities. With the advancement of modularization, which is a major trend in the automobile parts industry, the role of finished car manufacturers has been shrunk and primary cooperative companies has been growing in their importance and company size. In this situation, it is strongly required to establish online B2B portals for cooperation with small part manufacturers. Thus the present study purposed to implement WebService by mapping existing EDI standard forms using ebXML platform, which is regarded as the international standard of B2B e-commerce. The implemented WebService facilitates interaction and integration with existing applications using REST technology, which was applied in order to solve problems in ORPC-based distributed application environment including single vendor solutions, the requirement of high‐performance environment based on management network and firewall/proxy problem.