Guided by both the interactionist and sociocultural learning theories, this study investigates the interactive communications in text-based synchronous computer-mediated communication (SCMC) and face-to-face (FTF) oral communication environments and the impacts they bring to subsequent L2 Chinese speaking. Learners' perspectives on using text-based SCMC and FTF conversations to prepare for oral presentations are also examined. Through quantitative and qualitative analysis and case study analysis, the current study revealed both similarities and differences between the two interactive learning environments and their impacts on subsequent speaking performance. From the interactionist learning perspective, both learning environments provided opportunities for learners to generate comprehensive input and output and engage in negotiation of meaning. The linguistic and ideational resources discussed in the two interactive environments served as good preparations for learners' subsequent individual speaking. However, FTF communications generated significantly more language output, number of turns, and language-related episodes (LREs) and showed significantly higher content richness than text-based SCMC, whereas text-based SCMC showed significantly higher syntactic complexity. Post-FTF speaking performance demonstrated significantly better fluency, more diverse and advanced lexical usages, and richer content, whereas post-SCMC speaking performance was syntactically more accurate, had more complex syntactic features, and received higher holistic ratings. Examining from the sociocultural learning perspective, while both learning environments allowed learners to collaborate and contribute to the co-construction of language and ideas, the two modes differed in the degree of equality in learners' participation and the extent to which learners performed languaging and peer scaffolding. The results showed that language contribution in text-based SCMC was more evenly distributed than in FTF conversations, suggesting a more equal learner participation. Moreover, although learners engaged in more LREs during FTF conversations, they did not necessarily transfer the discussed language forms to their speaking afterward. While both learning environments were perceived to be facilitative in helping learners prepare for individual speaking in L2 Chinese, learners perceived FTF communications as more efficient in eliciting peer scaffolding due to immediate clarification and feedback. The case study revealed that the two interactive learning environments exhibited differences in their affordances depending on learners' learning approaches and L2 speaking proficiency. [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.]