Socialsecurity system is one ofthe component partsin modern Western economic system ,to which much attentionis paid.Together with modern enterprisesystem ,marketsystem ,income dis tribution system and macro-regulation,itconstitutesthe marketeconomicsystem .The Westernso cialsecuritysystem isdividedintothreecategories:freeinsurancetype,coerciveinsurancetypeand citizen supplytype.Each hasits meritsandshortcomingsand mustbeadjusted whenfacingnew cir cumstancesand new problems.