Authorial voice is often identified as a key trait of successful writing in English rhetoric and composition, leading to research on its construction, development, and assessment in various types of written texts. Using Hyland's (2008) interactional metadiscourse framework, existing studies have also examined the use of particular voice-related element(s) across different writer groups. Few, however, have examined how L2 writers may construct voice similarly or differently in their L1 and L2 writing. The present study therefore examined voice strength and voicing strategies in L1-Chinese and L2-English essays composed by the same group of Chinese EFL writers. Paired samples t-test showed, surprisingly, that writers' L2-English voice was significantly stronger than their L1-Chinese voice, whereas subsequent text analysis of L1 and L2 writing samples further revealed differing linguistic, rhetorical, and discoursal resources employed by writers for voice construction when writing in two different language systems. Such findings extend Hyland's (2008) interactional metadiscourse framework on voice construction and offer important implications for L2 writing instruction and assessment.