International student mobility has been increasingly driven by economic rationales. However, the mere presence of international students in US higher education is inadequate to realize the non-economic values of internationalization, such as enhancing intercultural understanding. This dissertation, grounded in a humanistic perspective, examined international students' experiences by exploring their social networks. Drawing on data from 53 in-depth interviews with international students at a four-year public research university in the Southwest US and employing ego-centric social network analysis (SNA), this dissertation comprises three empirical studies, focusing on international students' social integration, social support, and cultural adaptation, respectively. The first study presented a new scale for assessing international students' social integration, considering their social interactions with cross-national and cross-racial individuals. The findings revealed no significant differences in social integration between Asian and non-Asian international students and constraining and overlapping foci of activity functioned to foster international students' social integration. Focusing on social support, the second study showed that different social groups provided different types of support, with Americans supporting international students' cultural adaptation and emotional well-being, co-nationals offering life services, and other internationals providing academic support. Network-related characteristics, such as tie strength, degree centrality, and network density, influenced some or all types of social support. To further explore the nuanced meanings of cultural support, the third study introduced a two-level model for international students' cultural adaptation. The distinction between these two levels was whether students' knowledge and skills are fundamentally required for the function of their daily lives, as well as for academic and professional success. Americans supported international students' cultural adaptation at both levels, while co-nationals and other internationals' support primarily contributed support at the functional level. These three studies contributed to the literature by advancing the concepts of international students' social integration, social capital, and cultural adaptation. Methodologically, this dissertation demonstrated the benefits of employing SNA in international student research, including providing rich data on the individual students' uniqueness and their experiences across multiple dimensions. The practical implications of these findings offered actionable solutions for higher education institutions to support international students and facilitate intercultural interactions on campus. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]