Business group is a collection of an integrative, supportive, serving, coordinating affiliated firms. This study analyzed the data to explore the relationship between entry mode and key success factor (KSF) of overseas investment groups. The result showed positive correlation between large investment scale and KSF within business group in Taiwan, and vice versa. When further considering the factors of host country characteristics, industry characteristics, human resources, a business group without possessing exquisite and follow-up plans will not be successful. The important contribution of this paper is to provide Taiwan’s business groups which are willing to invest overseas with key success factors which should consider before their entries and can increase the possibility to be successful in overseas investment. Furthermore, this research studied the operation of Taiwan’s business groups by deep interview, and induced the key factors for mid-to-small sized companies to reach success when engaging in overseas investments. Hypotheses which are developed in this research can be used by both academic and business fields. Key words: group business, entry mode, key success factor (KSF)
