According to the theories of demand-following and supply-leading,there are two general patterns to form reinsurance center,that is,naturally occurring type and government construction type.According to domestic supply and demand environment and international competitive environment,Shanghai reinsurance center is completely impossible to form naturally,and can not be entirely government-building type.In this regard,this paper describes the different formation patterns and characteristics of international reinsurance center,analyzes domestic and international environment which Shanghai faces,puts forward to the unique formation patterns of combination of market development and the Government?s promotion.