Today, In the Service Industry are more getting a lot of convergence of IT utilization. And global IT companies are strengthening that platform based Services Ecosystems. These business in the field, Ecosystem Competitive strategy is difficult to imitate. And this strategy is generated organic Business Model that a by Competitive-Predominance to brings. In addition, the added value of the Service Industry is taken, a new type of job creation by the ripple-effect is huge. However, existing the Ecosystem Theory of Business is a lack of research on the use. Thus, Ecosystem Construction conditions is very difficult. This study is try to successful Platform Case's Analysis such as Apple, Google, Amazon, eBay's. These Ecosystems is that want to know the Major attributes. At first, would be analyzing to previous research, the Service and Knowledge Services' major attributes and Ecosystem studies' major attributes to grasp. Then, from a Group of Experts is to assess the importance. Finally, according to each Platform, examined the Correlation of Major Attributes.