This qualitative study explores how a French-Chinese web collaborative blog-writing project provides a space for understanding the various metalinguistic approaches that foreign language learners’ use to facilitate foreign language learning and intercultural communication. It adopts a multilingual-plurilingual approach, an interlingual approach and a web collaboration approach as a framework. Qualitative data was collected from the blogs and online interactions of 22 French Foreign Language (FFL) learners in China, and 24 Chinese Foreign Language (CFL) learners in France. The findings reveal the increased development of FFL and CFL learners’ metalinguistic awareness, plurilingual competence, and bilingual skills that is accomplished through web collaboration. Implications regarding web-based tandem language learning and peer-assisted web collaboration are discussed.