This study investigated the comparative effects of strategic and unpressured within-task planning on second language (L2) Chinese oral production and the role of working memory in mediating the effects of the two types of planning. Twenty-nine L2 Chinese learners at a large New Zealand university performed a narrative task after watching a 6-minute silent movie, followed by an operation span test gauging the learners' working memory capacity. The results revealed that (1) strategic planning enhanced fluency and unpressured within-task planning led to greater accuracy and syntactic complexity, (2) strategic planning facilitated the production of a syntactically transparent structure, while unpressured within-task planning showed an advantage for opaque, complex structures, and (3) working memory was drawn upon in unpressured within-task planning, but barely so in strategic planning. The data show that strategic planning benefits the Conceptualizer while unpressured within-task planning favors the Formulator. The data also suggest that the role of cognitive abilities in task performance is contingent upon the processing demands of different task conditions.