本研究觀察臺灣新上市公司上市後所從事的盈餘管理行為是否傾向於下半年或第 四季，並參酌國內股市相配合之資訊與競爭環境，由求實性會計理論之推衍，探討公司管理 當局從事年度間盈餘管理的傾向時機；並進而從盈餘與股價間之關聯性加以推衍探討盈餘管 理與盈餘事件研究之間的關係，是否越接近年度盈餘結算時，利用盈餘管理來達到未預期幅 度的操控，其價值越高。本文採用市場模式衡量異常報酬，並比較年度間各類之淨應計項目 ，以探討盈餘有用性、盈餘管理之傾向，及其是否產生股票有利的異常報酬。

　　　　　It is evidenced that the management of a firm would manage its earnings for certain purpose, e.g., application of initial public offering (曾國禓，1995) . In addition, the earnings have significant information contents (陳志愷，1992) . Thus, it is important in examining the relationship between the earnings management and information contents of earnings, This study hypothesizes that a firm would focus its earnings management activity in the fourth quarter. The intuition behind the empirical tests is summarized as follows. Due to managerial incentives for income-increasing biases, and the opportunity provided managers to engage in such biases for non-audited quarterly reports, investors perceive less strongly to interim good news reports than to interim bad news reports (Chambers and Penman, 1984).