The objectives of this dissertation are to examine how expatriates¡¦ social network affect the ability of access information/resource and knowing- whom capital on their career advancement, as well as the effects of perceived organizational support correlate to host and home social network. Specially, this research investigates dual sources (host and home office) of expatriates¡¦ network in order to understand the impact on the network abilities and extent. Through confirmed factor analysis of pretest data, measurements were refined and the questionnaire used for the study was developed. For the study, 267 surveys were used for the data analyses. Structural equation modeling in LISREL 8.8 was employed to analyze the relationships among the latent constructs. The findings from the study revealed significant relationships between 1) expatriates¡¦ social network of host office and access information & resource, 2) social network of host office and knowing whom capital, 3) expatriates¡¦ social network of home office and access information & resource, 4) access information & resource and career advancement, and knowing whom capital and career advancement. This study contribute theoretically to the expatriates dual social network literature by clarifying the relationships among host social network, home social network, social network abilities and career advancement, while the previous studies focus on expatriates host country context. This research findings pointed out the expatriates not re-establish a personal network in the host environment but still keep contact with his/her home social network. The expatriates¡¦ host social network has direct and strong effect on access to information/resources and knowing-whom capital. And the expatriates¡¦ home social network also has positive impact on access to information/resources. This empirical model also provides future research with a new angle of view over expatriates social network and career advancement.