More and more retailers sell Extended Warranty(EW) service with the increasing competition in the market Considering a supply chain where both the manufacturer and the retailer sell EW service，the retailer has two different strategies: selfoperated mode(sell EW service provided by the retailer) and reseller mode(resell EW service provided by the manufacturer) By using Stackelberg game，constructing a competition model between the retailer and the manufacturer，this paper gives the optimal profits under these two different strategiesFinally，we study the impact of relevant parameters on the influence of retailers EW service strategiesWe find that when the retailers EW service cost was small，the retailers EW service pricesensitive coefficient was small，the optimal strategy is selfoperated mode When the competition EW service pricesensitive coefficient was small and the retailers EW service demands were small，the optimal strategy is reseller mode