本文对以前认为李鸿章在签订李福协定时存在的违旨问题进行了辨析。经过将清廷授权和李福协定内容进行比对,认为李鸿章基本是按照授权谈判的。传统说法在藩属、通商问题的理解上存在误解。李福协定中放弃越南的关键原因,是甲申易枢后清廷对越目标发生变化,把保护越南看作是李福协定后的善后问题。 This article analyzes the problems of illegality existed when Li Hongzhang signed Li Fu’s agreement. After comparing the Qing authorization with the Li Fu agreement, Li Hung-chang basically agreed to negotiate according to the authorization. The traditional version of the vassal, the understanding of the issue of trade there is a misunderstanding. The key reason for the abandonment of Vietnam in the Li Fu agreement was the post-Shanghwei issue that the Qing court changed its goal toward Vietnam and viewed Vietnam as a post-Li agreement.