What did Chin Sheng-t'an do in his commentary on the Shui-hu chuan﹖Is it a systematic theory of the novel or a mere idiosyncratic reading of the text ﹖ Through a comparative study of Chin Sheng-t'an's and Roland Barthes's running commentaries on the novels they studied, as well as other modern Western theorists' articulation of what constitute a literary theory and an interpretation theory, this article offers a meta-discourse on the nature and status of Chin's commentarial discourse. It dissects Chin's commentary into two components: a structuralist phase of theory formulation and a post-structuralist phase of critical interpretation. Via such an anatomy, it comes to the conclusion that although Chin Sheng-t'an's reading of the Shui-hu chuan is indeed iconoclastic and rather stretched, the descriptive apparatus and reading strategy that he designed are effective and theoretically sound, and thus his commentary is a systematic theory of the novel.