根據傅惜華《清代雜劇全目》所著錄，清雜劇在劇本之創作領域而言，數量驚人，「姓名可考之清代雜劇作家作品，計五百五十種，無名氏雜劇作家作品，計七百五十種，共計一千三百種。」，雖如此，已難挽雜劇日薄西山之頹勢，中國戲曲史上，由元雜劇之光輝燦爛而南戲文、明清傳奇、花部地方戲，各領風騷，不遑多讓；至清，雜劇之發展空間，乃日漸迫蹙，數量雖多，已逐漸轉入案頭，無法演出。雜劇逐漸淪為文人抒情寫志之文體而已，一劇作罷，親朋好友，傳鈔借閱之餘，順勢將作者之旨趣，發為序跋數篇，以應其旨，以媚其情，甚而藉以品評劇本、抒懷吐臆，久之乃構成此期序跋之特色，戲曲理論因之更邁前步，是又為清雜劇之另一特質。 此期之戲曲理論有以專著之形式出現者、有散見於文集雜記或附載於他書中者、有自書中整卷輯成者、亦有散見於各曲論、曲律、曲選、戲文、雜劇、傳奇之序跋中者；一九八五年大陸學者蔡毅以三年時間，廣為收集，完成《中國古典戲曲序跋彙編》一書，除少數地方圖書館及私家收藏不計，全書共計「作家五百四十餘人，著作一百六十餘部，劇目七百七十六種，收序跋條目為二千一百九十條。」可謂工程浩大。此書之價值，有助於對中國古典戲曲之理論、批評、文學、美學甚至於戲曲目錄學、校勘學、史學做更上層樓之探討。而其所謂序跋之範圍頗為廣義，並不僅限於在著作前後，作者或他人所寫之序或跋，還包括與序跋同類之「題詠、弁言、小引、凡例、規約、贈言、總評、本事、問答」等等各種有關劇作的文字，亦一併選入，然純係贈答應酬性質為主，而無多少參考價值的題詞則不錄。 本文以該書所收清雜劇113種、可考作者66人之283篇序跋為範圍，擬將序跋中有涉及戲曲理論之部分歸納為四大類：動機論、戲曲史觀論、創作論、批評論等，做詳細之歸納與討論，庶幾於清代戲曲理論之深入探討有所稗益。

　　　　　According to Qingdai tsa-chu quanmu（the complete catalogue of the tsa-chu of Qing dynasty）, edited by Fu xi-hua, there are 1,300 plays produced in Qing Dynasty, among which 550 by ascertained playwrights and the other 750 by anonymous ones. In spite of such an amazing achievement, Qing tsa-chu had come to the end of its era. It was an inexorable trend for the development of tsa-chu. The golden age of Chinese drama originated from the Yuan tsa-chu, then nan xi-wen（southern dramatic scripts）, Ming-Qing chuan-qi drama, and hua-bu di-fang-xi（a local drama other than kun-qu）. Each had played a major role on the stage of Chinese drama. Till the Qing dynasty, the space for tsa-chu had been smaller than ever before. Gradually it turned out to be "Qu on one's desk "which meant it would not be put on a performance. Instead of a play, it transformed to a literary style that revealed literati's emotions and ideals. Once a playwright had finished his scripts, he would have pass round his works among the relatives and friends for perusal. After reading, some of the readers would write prefaces or postscripts to sympathize with or even criticize the writer's opinions. This fashion constituted the features of prefaces and postscripts in this period and also made great strides towards drama theory. The drama theory during this period was written in forms such as monograph, articles scaterred in collected literary works , appendix to a book, and xu-pa （prefaces or postscripts）of the qu-lun, qu-lu, qu-xuan, xi-wen, tsa-chu, and chuan-qi. It took Chinese scholar Cai yi years of hard work to compile Zhongguo gudian xi-qu xu-pa huibian（The collection of xu-pa of Chinese classical drama）, among that, there are more than 540 playwrights, 160 pieces of works and 776 plays included, and also 2,190 paticulars of xu-pa collected. This great work is valuable to the succeeding researches on the Chinese classical drama theory and critism, literature and esthetics, and even on the areas of xi-qu mulu xue（bibliography）, jiaokan xue（textual criticism） and shi xue（history）. The xu-pa called in this book is a generalized term, including not only the xu or pa but also the other forms of drama-related writings as ti-yong, bian-yan, xiao-yin, fan-li, gui- yue, zeng-yan, zong-ping, ben-shi and wen-da, etc.. But some ti-ci （inscriptions）written out of courtesy are not collected. In this paper, 283 pieces of xu-pa related to 113 plays by 66 ascertained writers of the above-mentioned book are chosen and classified into four categories according to the drama theory: "motivation theory", "drama historical viewpoints theory", "creative writing theory" and "criticism theory". I have a detail discussion on each category with the aim to do some help to the researches of Qing drama theory.