Since its operation on July 2008, Taiwan's Intellectual Property Court has gradually tended to become more specialized and efficient in patent litigation, especially for the patent infringement litigation, in accordance with the regulation of Article 16, Intellectual Property Case Adjudication Act, the accused infringer is frequently proposed the plea of patent validity, which including the claim of application for "Means Plus (Step) Function Language", and it may possibly limit and reduce the effectiveness of patent claims which results in lowering the possibility of patent infringement for the infringement-accused object; therefore, the "Means-Plus-(Step)-Function Language" will become one of important strategies for accused infringers with dealing infringement litigation. Currently, Taiwan's legal system still lacks of the proper and detailed regulations for "Means-Plus-(Step)-Function Language", and only related laws or regulations are the Examination Guidelines for Computer Software Related Inventions which promulgated and implemented on 1998, and Paragraph 1, Article 18 of Enforcement Rules of the Patent Law that promulgated and implemented on 1 July 2004. In addition, through the analysis of the Civil Decision of 2009 Min-Zhuan-Shang-Yi-Zi No. 3 that made by Intellectual Property Court, this study has conducted the discussion on the decision whether the technical features of patent claim included the "2008 Computer Software Related Inventions" for Means Plus Function Language; however, if the patent claim is not the "Computer Software Related Inventions", then whether the "Examination Guidelines for Computer Software" is applicable or not. As a result, this study is hoped to decrease the dispute about the applicable laws or regulations for the patent claims of Means-Plus-Function Language.