Aiming　at　the　problem　of　how　to　apply　argument　into　multi-agent　negotiation　in　the　context　of　E-commerce,　two　main　issues　are　discussed　in　this　paper:　when,　and　how　to　add　argument　into　traditional　negotiation　system　in　E-commerce.　A　negotiation　mode　of　argumentation-based　negotiation　in　E-commerce　is　proposed.　Furthermore,　an　argument　generation　mechanism　is　proposed.　At　last,　a　negotiation　prototype　system　is　designed　and　realized　to　demonstrate　how　argument　being　used　in　multi-agent　negotiation　system　oriented　to　E-commerce.　©　2012　IEEE.