《左傳》據事宜書，紀錄了各種禮典，包括冠、昏、喪、祭、饗、射、朝、聘，其中聘禮尤備，還有豐富的軍禮。自漢迄清，注家無不以“三禮”通釋《春秋》、《左傳》禮制。楊伯峻《春秋左傳注》可說是以“三禮”通釋《春秋》、《左傳》禮制的集大成者。其實，《左傳》與“三禮”所言禮制，實有合有不合。兩者相合，自可博采禮文，互為印證；若其不合，不能強相牽附，必須自行根據《春秋》、《左傳》本文建構春秋禮制。本文以個別禮制為焦點展開討論，然從聚點成面，嘗試勾勒《左傳》禮制與“三禮”合與不合的輪廓，主要看眼於兩者的同中有其之處，探討致異的因由，并歸納出其間的通例。簡言之，《左傳》禮制與“三禮”相合，原因易明，要麼兩者都是周禮或更早期的禮制，要麼都是春秋時禮。兩者同中有異，成因較為複雜，大抵有五種可能：一、“三禮”所載為時代較早的禮，或即周禮，而《左傳》則為時代較晚的禮，可稱春秋時禮；二、情況剛好相反；三、《左傳》反映春秋時期國別禮異的現象，而“三禮”所記則局限於某國的情況；四、“三禮”雖以事實為基礎，但經後儒改定規範、整齊劃一或增飾附益，而《左傳》則紀實，前者實中有虛，而從者則純實；五、《左傳》紀實，而《禮記》、《周禮》所記并無實據，只能視作禮說。 Since the Han period 漢代(202B. C. -220A. D. ), Chinese literati have thrown in much effort to the study of the ritual elements recorded in the Spring and Autumn Annals and the Zuozhuan. While fruitful results have been achieved by applying Sanli to the interpretation of these ritual elements, yet little has been done on the comparison between these books. Based on the findings of previous scholars like the Qing scholar Yau Jiheng (姚際恒) (1647-1715) and Yang Bojun (楊伯峻) (1909-1992), the present article conducted a thorough comparison of the ritual elements contained in the Zuozhuan and their counterparts in the Sanli and reached the conclusion that , although Sanli and Zuozhuan agreed with each other in respect of various rituals , there are considerable discrepancies between them. The discrepancies are mainly due to the transformation of rituals at different times and difference of rituals and practices among the states of the Spring and Autumn period. On the other hand, the agreements between the Sanli and the Zuozhuan prove that the etiquettes and rituals found in the Sanli were describing people's ritual behaviour during the Zhou Dynasty and the Spring and Autumn period.