The unpredictability of Semiconductor Industry Cycle and high business risk from high Capital Expenditure (in short Capex) result in IDM¡¦s (Integrated Devices Manufacturer) preference in ¡§Asset Lite¡¨ strategy. The key approaches are reducing Capex in in-house facilities, joint-venture Fab with other semiconductor companies, sell production facilities to foundry or SATS (Semiconductor Assembly and Test Service), spin-off part of semiconductor division to have better differentiation and even joint-venture with SATS, in one word, the structure of semiconductor industry is in transition stage. This study is to review the evolution process of semiconductor industry from only IDM in 60 year ago to the rise of Fabless company who is playing a very key role in some semiconductor devices. IDM had started to do outsource business and decided to increase the business volume. We are going to understand what influence Fabless had caused in the industry and how IDM could adjust itself toward outsourcing strategy.