Much research has been completed that focused on the role of drafting strategies in first language (L1) writing, but its role in second language (L2) writing is missing. The present study investigated the impact of outlining and free writing strategies on L2 academic writing in terms of overall quality, as well as more specifically in terms of content, organization, and coherence. Sixty Japanese L2 Chinese speakers, studying at a major research university in western Japan, were randomly divided into outlining, free writing, and control groups. They wrote argumentative essays. Using an academic writing rubric, two raters assessed the essays. Results revealed that free writing strategy improved the coherence of the text, which follows the Interaction Hypothesis. Outlining improved not only the overall quality of L2 academic writing but also the content and organization of the text. These findings, which are in contrast with some L2 writing research, support the Overload Hypothesis.