This　paper　studies　the　coordination　problem　of　a　supply　chain　with　one　supplier　and　one　retailer　under　market　scale　and　production　cost　disruptions,　where　demand　function　is　nonlinear.　The　optimal　emergency　strategies　arc　obtained　for　different　disruption　conditions　under　the　centralized　mode.　The　result　shows　that　the　original　production　plan　has　some　robustness,　but　the　retailing　price　always　needs　to　be　adjusted　according　to　the　different　disruptions　in　order　to　maximize　supply　chain　profit.　For　the　decentralized　model,　when　market　scale　and　production　cost　are　disrupted　by　the　emergent　events,　it　is　proved　that　the　supply　chain　can　be　fully　coordinated　by　adjusting　the　price　discount　policy:　the　all-unit　quantity　discount　policy　and　the　capacitated　linear　price　policy.