A support system for multi-party and multi-attribute e-business negotiations was built to support e-business negotiations effectively and to expand the practicability and extensibility of existing negotiation support systems (NSS).   The demand for negotiation support of e-business among enterprises was analyzed.  A framework for supporting multi-party and multi-attribute negotiations and their decisions is proposed, based on generic multiparty negotiation protocol.  A proto-application was built and a negotiation experiment was conducted to prove the usefulness and ease of use of the proposed framework.