本論文研究，根據之實證結果可歸納如下： 一、IPO公司於自願集保閉鎖期間結束日前後有顯著之負值異常報酬。 二、自願集保成數高之IPO公司相較強制集保成數高之IPO公司於三個月閉鎖期間結束日前後有顯著之負值異常報酬。 三、以科技事業IPO公司於三個月閉鎖期間結束前後之異常股價報酬大於一般IPO公司。 ;In the research, we want to investigate the stock reaction at the period surrounding voluntary lockup expiration. This is different from most internal academics, mainly focus on the point about the period surrounding involuntary lockup expiration, had studied before.In order to know about the stock price relationship between the end period surrounding involuntary and voluntary lockup expiration, we collected the company listed at stock exchange market and over-the-counter market from the period 2006/01/01 to 2014/12/31 as the sample data which will be distinguished into Technology-based enterprises and other enterprises for our research. In addition, due to most equities are concentrated in people come with the company as the shareholders, we also assumed that the behavior of stock selling will significantly related to the end period surrounding involuntary lockup expiration in Technology-based enterprises with other enterprises. According to our investigation, we can sum up: 1. IPO companies will suffer from abnormal return with negative values significantly during the end period surrounding voluntary lockup expiration. 2. IPO companies which has highly percentage of voluntary lockup rate will suffer from abnormal return with negative values significantly during the period of 3 month lockup expiration compare with IPO companies which has highly percentage of involuntary lockup rate. 3. IPO companies in Technology-based enterprises will receive abnormal return significantly during the period of 3 month lockup expiration compare with IPO companies in other enterprises.