國際間，專利侵權新聞屢見不鮮，且專利侵權訴訟影響公司股價漲跌，當訴訟案發生時，隨著新聞消息之發佈，市場如何反應公司價值與面臨專利侵權訴訟時對於投資報酬之影響程度分析亦較為缺乏的。本研究以事件研究法探討專利訴訟時，原告公司與被告公司之資訊價值變動情形及企業的競爭環境下，不同的專利訴訟來源其資訊價值之差異為何？本研究期間自1998年1月1日至2010年10月31日共12年。實證結果顯示專利訴訟可能帶給投資人或內部持股者產生負面的觀感，亦有可能此事件為套利的投資機會，五力分析下各訴訟來源發生專利訴訟時皆為不利消息，事件後出現反向修正的現象，使股價盤整回合理的價格，故侵權訴訟事件在台灣市場並不看好對原、被告公司而言皆處於負向的消息。
International patent infringement news often happens in recent years, and patent in-fringement litigation often affecting the company stock price. When patent infringe-ment news release , how the market reaction and the face value of the compa-ny for patent infringement litigation impact analysis of return on investment is al-so relatively lacking.
This report uses event study to research patent infringement in company competitive The plaintiff and the defendant company's value variation, and what’s difference from different sources of patent litigation, The study period from January 1, 1998 to 2010 October 31, 12 years. Research results show that Patent litiga-tion may give investors or shareholders within the negative perception, this event may also invest in arbitrage opportunities, five forces analysis of the source under the action occurs when the patent litigation are all bad news, events after the reverse correction of the phenomenon, the share price correction back to a reasonable price, so the infringement lawsuits in the Taiwan market is not optimistic about the original, the defendant companies are in the negative news.
