公案劇在現存元雜劇中佔有超過十分之一的比例，在內容上是一個很特殊的劇種。它多半描寫犯罪、偵查與審判，或爲無辜者洗冤平反，或使真凶伏法。由於書寫法制文化的各個面相，公案劇的題材迥異於其它劇種。筆者認爲公案劇中對法律所作的各種戲劇呈現有加以討論的必要。本文第一部分，探討公堂淚痕在公案劇中的戲劇效果，其次探討與之對立的科諢內容與作用。並借用巴赫金(Bakhtin)的｢嘉年華｣(carnival)理論，來分析公案劇中的科諢所具備的揶揄諷刺意涵。以期得知，劇作家如何利用兩種手法呈現淚中有笑的特殊美學。第二部分，探討公案劇特有的法庭雄辯。第三部分，探究公案劇如何運用法律的各個技術層面去增色一齣雜劇的文學性與娛樂性。

Courtroom drama constitutes over ten percent of the Yuan zaju plays still available today. This is a special genre about crime, investigation, and trial. It often presents cases of injustice reversed or of the real criminals punished by wise judges. The subject matter of this genre, covering many aspects of litigation, is unique in the repertoire of Yuan zaju. This article discusses presentations of the Yuan dynasty courtroom drama in three aspects: 1) Tears shed as well as farces enacted in the courtroom and their dramatic effects, 2) Displays of courtroom eloquence, and 3) Applications of legal elements to the plays for literary and entertaining purposes. To put my discussion into perspective, I have applied Baktin's theory of the carnival to analyze the sarcastic functions of the farces and to see how laughter works with the opposing force of tears.