Recently, software distribution method, along with advent of era of Web 2.0, is rapidly evolving from ASP(Application Service Provider) method into SaaS(Soft as a Service) method due to development in concepts and technologies including SOA(Service Oriented Architecture) Web Service, On Demand and Component. Determining factor in market competitiveness of newly emerging SaaS business model will be analyzed by focusing on Group-Wares, POS(Point of Sale) System, CRM(Customer Relationship Management) and ERP(Enterprise Resource Planning), which are the most representative SaaS business models in Korea. It is anticipated that the outcome of analysis of determining factors for market competitiveness for each of the main SaaS Business Models acquired through questionnaire survey can be utilized as important benchmarking material in setting the direction of cultivating SaaS market by the government as well as new entries into SaaS market.