盈餘對公司來說是最簡單、最直接之績效衡量指標，故盈餘之報導對公司相當重要，也因此過去有關盈餘管理及損益平穩化行為之相關研究將重點放在報導水準受到各種因素、各類利害關係人之影響。公司之控制權掌握在股東手中，因此股東對盈餘報導之影響不容忽視；但股東（同時也是投資人）之投資目的及投資策略不盡相同，對盈餘之影響亦可能不同。此外，同產業之公司間會因投資人對其所做之相對績效評估而有相互競爭之行為，致使同產業之行為可能有趨向一致之情況，不同產業則可能不同。 　　本研究以民國八十三年至民國八十八年為研究期間，針對我國上市公司研究其損益平穩化行為，從股權結構觀點（以長、短期投資之股東持股比率）探討其與公司損益平穩化行為之關係，藉以瞭解投資人之投資目的不同對公司長期盈餘之趨勢有何關聯性。其次，針對我國電子產業與非電子產業進行產業效果之研究，探討損益平穩化行為之不同是否與產業有關，以及電子產業損益平穩化之傾向。 　　實證結果發現：(1)公司之平穩化行為與股權結構有顯著關聯性；(2)當公司長期投資之股東持股比率愈高時，公司傾向不採行損益平穩化；(3)當公司短期投資之股東持股比率愈高時，公司愈傾向平穩化其損益；(4)產業因素與我國上市公司損益平穩化行為有顯著關聯性，不同產業之平穩化行為不同，且電子資訊產業傾向不從事損益平穩化。 / Earnings is the simplest and most straightforward indicator of a company's performance. Therefore, earnings reporting could be a crucial concern for an investor's decision-making. There are a lot of researches regarding earnings management and income smoothing focused on how the role of stakeholders and other possible factors would affect the accuracy of a company's earnings reporting. For most companies, their shareholders control the core business activities, and thus it is hard to ignore their impact on the earnings performance. However, due to the discrepancy of investing policies and activities of different types of investor, the extent to which the types of shareholders could influence a company's earnings can be varied. Besides, since companies in the same industry always compete for better performance resulted from investors' relative performance evaluation, there is also a trend that the companies in the same industry would behavior in a similar way when reporting their earnings. 　　In order to prove that there's a significant relationship between a company's trend of reported earnings and its shareholders' investing goals, this thesis collects the overall market data from 1994 to 1999 and then examines each company's income smoothing behavior. In addition to testing whether a company's decision to exerting income smoothing is contributed to the portions of long-term and shot-term shareholders, this thesis also tries to identify whether the industry effect exists among the electronic industry and other industries that can make different industries have discrepant income smoothing behaviors, and find the electronic industry's income smoothing intent. 　　The empirical results document that: (1) A company's income smoothing behavior is significantly related to its ownership structure; (2) A company with larger portion of long-term shareholders tends to not adopt income smoothing strategy; (3) A company with larger portion of short-term shareholders tends to adopt income smoothing strategy; (4) The industry effect is significantly related to companies’ income smoothing behaviors. Different industry has different pattern of income smoothing behavior. The companies in the electronic industry tend to not adopt income smoothing strategy.