Recent studies on Chinese-English contrastive rhetoric have argued that there is actually little to contrast and the traditional "qi" (beginning), "cheng" (transition), "zhuan" (turning), "he" (synthesis) structure has little influence on contemporary Chinese writing. A comparative analysis of select online instructional materials on argumentative writing for American and Mainland Chinese school writers reveals that although the two groups agree on the purpose, tripartite structure, and the use of formal logic, they differ in the discussion of some fundamentals for argumentative writing. Specifically, the American group considers anticipating the opposition a must while the Chinese group demonstrates epistemological and dialogical emphases and highlights the need to use analogies. The importance of analogies and epistemological and dialogical emphases can be traced to ancient Chinese rhetorical theories. This paper argues that the findings may help us to understand the assumptions and beliefs that underlie rhetorical conventions or textual features. Further comparative research on Mainland Chinese and American pedagogical materials on argumentative writing is suggested.