The continuously evolving IC industry has driven an IC design service to become an emerging sub-industry to the semiconductor value chain. This emerging business manages the entire chip development manufacturing process and applies third party's resources when and where its customer needs them. To keep the customer as their main focus and deliver what the customer truly needs, a strong and committed partnership ecosystem is more important than ever. Therefore, the objective of this study is to explore the partnership network of Taiwan's IC design service companies by applying the co-evolutionary theory in business ecosystem. The partnership network is analyzed together with the corporate data such as revenues and milestones. The finding shows that, the firms have accumulated and created their competitive advantage through partnership with various leading manufacturers, IP vendors, and EDA tool providers in order to leverage their technological capabilities over time. While the production ecosystem is being localized in Taiwan based on the benefit of the complete value chain, the IP ecosystem is more internationalized. This study contributes to the understanding on the characteristics of the emerging business in a highly competitive environment. It should also provide policy implications for the industry stakeholders and government about new opportunities in high competitive value chain.