本文試圖從《水滸傳》構成之過程，包括其整體結構、忠義觀念，尤其是宋江此小說人物如何被塑造之角度，來討論金聖歎在這幾方面的詮釋(包括改動)可能造成的缺失。第一節分析歷史上的宋江如何變成文學裡的宋江，包括是否托受招安、征討方臘等問題之探討；以此批判金聖歎腰斬水滸之不當。第二節著眼於忠義觀念之討論，從《大宋宣和遺事》長篇話本裡即有玄女娘娘給宋江天書囑其廣行忠義的情節；明代刊行此書時，亦多冠上「忠義」二字，金聖歎必不許水滸英雄以忠義，等於否定《水許傳》的核心主題，怎能算是善解？第三節論及金聖歎對宋江形象之改動與批評，將原來圓型的複雜人物變成全然負面的簡單人物，然後貶之甚深，此種改動與詮釋實無客觀性可言。

　　　　　This paper discusses the mistakes of Jin Shen-tan’s金聖歎interpretation of the formation process of the Outlaws of the Marsh, including its whole structure, the concepts of loyalty and righteousness, and especially the molding of the main character, Song Jiang宋江. In the first section, the author analyzes the transformation of Song Jiang from a historical figure to a literary figure, and looks at questions such as the acceptance of amnesty and the expedition against Fang La方臘. The author’s aim is to point out how it was wrong for Jin to divide the Outlaws of the Marsh in half. In the second section, the author discusses the concepts of loyalty and righteousness. In the Tales of the Xuan-he Period of the Great Song Dynasty大宗宣和遺事, it is the Goddess Xuan-n?玄女who gave a book form Heaven to Song Jiang. Most of the versions printed in the Ming Dynasty are titled The Loyal and Righteous Outlaws of the Marsh. So, if Jin denies the loyalty and righteousness of the marsh heroes, he denies the central subject of the novel. In the third section, the author emphasizes that Jin makes a major change in the image of Song Jiang, and turn a complicated, well-rounded character into a totally negative, flat character. Jin belittles Song Jiang, and hardly looks at this character objectively.