In our country,there is no clear legislation of defense of publicly known technology,but its principle has been gradually established in the judicial practice.

The Influence of traditional knowledge on the prior art;

Research on the Prior Art under the Technical Information Perspective——In the Context of the International Harmonization of Patent System

The popularization of Internet and its particularity of information dissemination makes it necessary to deeply analyse its influence to the boundary of prior art.

This paper expounds the reasons and legal ground of the application of unconfined public technique defense,puts forward the conditions of applying unconfined public technique defense,and points out that the people s court should permit and support actively the application of unconfined public technique defense in the action for infringement of patent.

Meanwhile, the relief to the patentee under the application of the doctrine of equivalent should be restricted by the the doctrine of estoppel and the defense of publicly known technique.