所謂「概念」是透過一個語詞去理解、掌握一個對象，而這個語詞與概念本身所要掌握的對象息息相關。作為表現概念的語詞，要求具有精確性和普遍性的定義；以便能對於複雜的事件作出簡化的、概括的反映或分類。戲曲批評中的「概念」包括兩種，一種是古典劇論中已經出現的語詞，相當於「術語」（term），即以一個簡化的、概括的語詞，反映諸項複雜的批評理論。另一種是對具有共同關鍵屬性的一類對象、事件、情景、性質的反映，雖無特定術語名之，卻也蘊含某種概念。本文以戲曲批評中「務頭、文律、虛實、結構」四個概念術語，一則概述其定義內涵，勾勒其歷史發展；古代曲論家如運用這些概念進行實際批評，亦屬實踐層次。二則就個人所見所聞，略舉古典與新編戲曲，印證這些概念的具體實踐。這四個概念大約含括一齣戲由點線至全面的基本要素。大抵而言，不論故事有所本或無所本，先要選取題材，設置人物，擬定主題。繼而運用虛實技巧，組織關目。在情節布置中，安排曲牌體聯套或板腔體腔調，編撰文律兼美、當行本色的曲詞。在行動推展與衝突安排中，刻劃人物性格。劇本不論以分場形式或無場次結構，必須有務頭所在，成為一齣戲的情節高潮或感情高潮。本文試舉古典劇作《竇娥冤》、《琵琶記》、《牡丹亭‧遊園驚夢》、《長生殿‧聞鈴》，花部《兩狼山》；以及海峽兩岸新編戲曲，如京劇《鎖麟囊》（1940）、《徐九經升官記》（1981）、《曹操與楊修》（1988）、《美人兒涅槃》（1993）、《阿Ｑ正傳》（臺灣，1996）、《三個人兒兩盞燈》（臺灣，2005）；越劇《西廂記》（1990）；崑劇《梁山伯與祝英臺》（臺灣，2004）、《楊妃夢》（臺灣，2011），以及整編崑劇《尋找遊園驚夢》（臺灣，2007）、《長生殿》（臺灣，2009）等劇作，具體分析，印證戲曲批評概念術語，不僅止於理論層次，亦實踐於古典或當代戲曲創作，或可找到古今對話的意義。

”Concept” means understanding a subject through a word or phrase which is closely related the subject itself. There are two types of concepts in dramatic criticism. One is the existing words in classical dramatic criticism, which is equivalent to ”term”, meaning simplified and inclusive words or phrases self reflective to complicated theory of criticism. The other type of concept signifies a reflection of subjects, events, scenes, and qualities that share common attributes. There are no specific terms to name the latter type while it does embrace certain concept. This paper discusses four concepts, or terms, of dramatic criticism-wutou (務頭, impressiveness), wenlü (文律, language and rhythm), xushi (虛實, fictitiousness and actuality), and jiegou (結構, structure). First of all, I briefly describe the historical development and definitions of the four concepts. How dramatic critics applied those concepts to their criticisms is categorized as the level of practice. Secondly, based on what I see and hear, I list examples of classical and newly adapted plays and see how the concepts are used in real plays. The above methods support my argument that concepts, or terms, of dramatic criticism not only stay in the level of theory but also could be substantiated in classical or contemporary opera. Moreover, such a comparison-based methodology would also allow us to find out the significance in the conversation between classical and contemporary opera.