Like all the other literary works from the world, the writing of Chinese classical prose has its own rules. But these rules are often concealed and hard to be observed due to the great influence of the tradition from Han dynasty, which says that it would be better to practice rather than empty preaching. Excellent writers often avoid mentioning the rules they followed and dare not or would not speak up all the various consideration behind them, which sometimes makes it difficult for descendants to understand the secrets of success of their outstanding works. Yet, there are also some authors blindly following the old rules, regardless of the changes of the background behind them. This paper focuses on two pieces of prose — Jia Yi’s Guoqin Lun（Ten Crimes of Qin） and Qi Liaoshen’s Shitouji Xu（the Preface for Dream of the Red Chamber）, trying to provide insight into two hidden rules in Chinese classical prose writing and discuss their unique thinking logic. The writing rules of Jia Yi’s Guoqin Lun benefited from analogical thinking，namely, in order to lay out a new thing and its principle, the author started from some old similar ones which were well-informed in his own experience. Based on the using of analogy speculations, Jia Yi turned to the new narration so as to grasp the new things and their theories completely. The implicit logic behind this rule is, as long as selected similar people or things in history are listed together, it would be quite clear and self-evident what would happen to someone or something nowadays that has much in common with them. This kind of analogy thinking became more common in Stratagems of the Warring States. Also there are a large numbers of examples in Records of the Historian. But fundamentally this narrative way cannot be fully trusted because it is not starting from the thing itself but from the analogy. Many examples revealed the absurdity of this writing method. It would be specially mentioned that although Jia Yi’s Guoqin Lunadopted this eloquent narrative method, it avoided the defect of the analogy argumentation. In this sense, it is one of the best model of the traditional Chinese classical essays. Today，this kind of thinking method is still taken by some people. But others tended to abandon it due to the prolix writing. Qi Liaoshen’s Shitouji Xu displayed the multi-meaning of Dream of the Red Chamber. Though it was a quite exquisite article, it had a fatal flaw. Originally, a preface for a book in old times had a one-thousand-word limit. Hence the content of an article must not be carrying too much. If there is only one meaning in an article, it can more easily makes it thin and ordinary. The application of dialectics from ancient times, coupled with the Chinese characters with the feature of duality, gave rise to the writing model of ″one divides into two.″ It helped an article to be refined but complicated, succinct but mixed. To the most sophisticated part, it grasped and unified the contradictory and its transformation. From the point of view of a writer, this way was not only sufficient in describing objects comprehensively and exhaustively, but also made the article variegated and diversiform. From this perspective, Qi Liaoshen’s Shitouji Xu was an excellent work undoubtedly. But in this article, the author misappropriated the writing models of ″one divides into two″ and ″two becomes one，″ ignoring the fundamental changes from a short prose to an extended narrative one, which makes his praise of Dream of the Red Chamberwas not so consistent with the actual situation. Literati in Ming and Qing dynasties got so wrapped up in diction that they couldn't go a step further in writing. It must be said, though, that short classical prose was not suitable for describing much more complicated social life of the times. As a new literary style, long prose would come out ultimately.