本文內容主要可分為三大部分，第一部份是「本國銀行業逐年的競爭程度及其變化之分析」，主要是以Panzer-Rosse模型評估銀行業的競爭程度，實證結果顯示1996至2000年每年的金融市場處於壟斷性競爭或完全競爭，在考慮銀行業務差距頗大及極端值存在的可能之下，2001和2002年的銀行業為壟斷性競爭。相較於1996至2000年，2001至2002年銀行業的競爭程度有降低的現象。 第二部分是「銀行業的競爭程度與利息收入佔總資產比率之關聯性分析」，本文延伸Panzer-Rosse模型，以分量迴歸法取代傳統最小平方法，發現排除規模效果的影響下，位於利息收入的條件分配愈左端（即利息收入佔總資產比率較低）的銀行，其所處之金融環境競爭程度愈高。此外，亞洲金融危機受創最嚴重的五個東南亞國家，自金融風暴發生至2004年，位於經資產標準化的利息收入分配左端、或右端、或中間的銀行在各個國家雖遭遇不同的競爭環境變化，不過，平均而言，所有銀行面臨的競爭程度皆獲得改善。 第三部分是「以分量迴歸法分析會計盈餘的時效性與穩健性」，實證結果顯示會計盈餘對好消息認列的時效性和對壞消息認列的穩健性會受企業當期的盈餘水準所影響。若企業當期的盈餘水準愈差，則會降低其盈餘的時效性，但是會提高其盈餘的穩健性。相反地，若當期的盈餘水準愈高，則會提高其盈餘的時效性，但是會降低其盈餘的穩健性。 / There are three issues in this dissertation. The first one is to analyze the yearly degree of competition and its variation in Taiwan’s banking industry with the Panzer-Rosse model. We find that the markets over the period 1996-2000 were characterized with monopolistic competition or perfect competition, while the system was characterized by monopolistic competition in 2001 and 2002 after we take into consideration the possibility of outliers. Furthermore, the results also suggest that the competition has declined in Taiwan’s banking industry. The second topic is to investigate the relationship between banking competition and the ratio of banks’ interest revenues to total assets. The results show that while the ratio of bank’s interest revenues to total assets is lower, the bank faces a more competitive market. Moreover, competitive pressures have been improved for banks with different levels of interest revenues over total assets in East Asia after the financial crisis occurred in 1997. About the final issue, we try to find whether firms’ contemporaneous earnings affect the timeliness and conservatism of accounting earnings and their relationship. Our results show that the degree of timeliness and conservatism of accounting earnings are relevant to the level of earnings. Specifically, firms with poor earnings will decrease their earnings in recognizing good news but increase the level of conservative accounting. On the other hand, the level of conservative accounting is a decreasing function of earnings while the timeliness in recognizing good is increasing in earnings.