本研究之目的，乃在探討簽證會計師是否因其對審計客戶提供非審計服務與害怕失去客戶之恐懼，損害其獨立性，而影響其不出具保留意見。本研究以會計師對民國 75 年至 79 年上市公司財務報表所簽證之意見為樣本。

本研究為控制受查公司之固有風險，參考 Dopuch, Holthausen, and Leftwich (1987)所採用之財務變數與市場變數，以控制影響會計師出具意見之因素，其中包括總負債相對於總資產之變動、應收帳款相對於總資產之變動、存貨相對於總資產之變動、帳面資產總額、抽查年度是否虧損、上市時間、Beta 之變動、殘差項標準誤之變動，以及控制產業別之虛擬變數。本研究除控制固有風險外，亦控制固有風險外，亦控制新公報發佈之影響。

本研究首先採用簡單 Logistic 迴歸分析，發現當簽證會計師對其審計客戶提供之非審計服務水準愈高時，會計師愈不可能出具保留意見；本研究亦發現當審計客戶對會計師施加壓力時，會計師會透過其害怕失去客戶之恐懼，而轉變為不出具保留意見之壓力，亦即，本研究發現當審計客戶對會計師施加壓力時，會計師愈不可能出具保留意見。

本研究使用複 Logistic 迴歸分析檢定也發現當簽證會計師對其審計客戶提供非審計服務之水準愈高時，會計師愈不可能出具保留意見；當審計客戶對會計師施加壓力時，會計師愈不可能出具保留意見。此結果與簡單 Logistic 迴歸分析之結果一致。

The purpose of this study is to answer the question whether the CPA's issuance of qualified audit opinions is related to their rending of non-audit services and the fear of losing clients, which in turn affecting the CPA's independence. The CPA's opinion for the public companies was obtained from listed on the Taiwan Stock Exchange between 1986 to 1990.

The method used by the Dopuch, Holthausen, and Leftwich(1987). Study was used to control for the inherent risk. Financial and market variables included are the changes in three ratio (the ratio of receivables to total assets, the ratio of inventories to total assets, the ratio of liabilities to total assets), the total assets, current year loss, time listed, change in beta, change in residual standard deviation of returns and seven industry dummies. In addition to the control of the inherent risk, the study also controls for the effect of newly promulgated accounting bulletin.

The research methodology is as follows, First, this study applies the simple logistic regression analysis. The results of the analysis indicate the existence of significant relationship between qualified audit opinion and the level of non-audit services, the results also indicate that clients tend to push auditors under pressure and make them fell the fear of losing clients, so then the probability to issue qualified opinions is smaller.

Second, this study applies the multiple logistic regression analysis. The findings also indicate the existence of significant relationship between qualified audit opinion and the level of non-audit services and fear of losing clients.