Different from literatures in supply chain management which focuses on the role of revenue-sharing contract in coordinating supply chains，this paper mainly studies the effect of such contracts on upstream suppliers’pricing decisions，allocation efficiency and social welfareＲesults show that: in supply chains coordinated by a revenue-sharing contract，an upstream supplier imposes discriminatory pricing to downstream heterogeneous manufactures，which，along with downstream efficiency and product substitution，affects the allocation efficiency and social welfare．Though revenue-sharing can increase joint profits through coordination，the effect on consumer surplus and social welfare is ambiguous．This paper also discusses the effect of firms’relative bargaining power on the revenue-sharing proportion，and identifies factors affecting the revenue-sharing parameter．Finally，based on the analyzed results，it is suggested that，as a means of vertical restraint，the anti-trust examination on revenue-sharing should adopt the“rule of reason”rather than“per se illegal”．