The effective protection of the patent is necessary for achieving the patent law’s goal of encouraging innovation and the disclosure of patented technology. Therefore, the ability for patentee to effectively carry out the relief is an important consideration in patent law. Indirect patent infringement though not infringe patent itself, but have the effect of encouraging or helping others to infringe the patent. To ensure the effectiveness of patent rights, many countries have codified indirect infringement in statutory form. Analysis of the legislation of the U.S., Germany, Britain and Japan, the study found that based on different economic environment and social needs, these countries did not adopt identical criterion. The article compares the differences between the elements of foreign legislation, expect to find out points that worth our consideration when amending the law. In order to understand the current status of practice, I do empirical research on the R.O.C. court judgment. Focusing on the constitutive elements, try to found the opinion of the court. The result of the research suggests that majority of judgment held indirect patent infringement should subordinate to direct infringement. On subjective element, there are different opinions, some opinions held that prove the intent is necessary, but some held that negligence can be established. It is interesting to find that defendant’s subjective is associated with the relationship between direct infringement and indirect infringement in judgment. Reference to foreign legislation and observation of current law, the draft of amendment on indirect patent infringement had a right direction. The study look forward to resume legislative discussion. Taking into account the interests of patentee and the public interest, and establish a regulation comply with practical need and the domestic expectation.