Abstract: Transnational strategic alliance is an effective way of internationalizing and obtaining legitimacy in new entry environment for companies lacking resources and experiences. However, the lack of attention to the factors of organizational resources and capabilities will seriously affect the effective acquisition of legitimacy. In this study, we selected 36 cases from a database of 112 Chinese company’s strategic alliances, which is collected by ourselves, to carry out a mixed study aiming at looking into the mechanism of acquiring legitimacy in “going abroad”. Results show that resources complementarity works in two ways for companies to obtain legitimacy, and they will lead to different effects. This study shed lights on theories of legitimacy and will give guidance to legitimacy acquisition for Chinese company’s internationalization in practice.