The purpose of this research is to find a better win-win growth strategy of Large and mid-sized IT service enterprises. Efficient win-win growth for large and mid-sized enterprises is essential for acquiring a solid global competitiveness in IT service industry. However, previous studies lack generalized and detailed findings, and therefore past strategies were based on fragmented analysis. To develop an efficient win-win growth for Large and mid-sized enterprises, global benchmarking and an in-depth analysis on deep-rooted problems in IT service industry has been conducted. Past and present policies on IT service industry have been reviewed based on desirable co-growth structure. Based on research, current policies are unable to support co-growth, and collaborative efforts between Large and mid-sized enterprises as well as square deals are necessary for win-win growth. A new policy paradigm has been derived and a roadmap for efficient co-growth strategy has been suggested. The results of this research can be used for building a better IT service industry polices. In future studies, a longitudinal analysis on the proposed co-growth strategy can be conducted.