本文將公司所得稅及股東所得稅納入Feltham and Ohlson (1995)、Harrisand Kemsley (1999)及Zeng (2001)之異常盈餘模式中，延伸成為稅後評價模 式，此模式認為公司價值是「帳面價值」與「稅後淨利」的函數，在公司稅存在情況下，利息費用具有抵稅效果，因此財務資產所產生的異常財務盈餘不但存在，而且可能增加公司價值。在稅後評價模式下，本文預期負債融資績效會對異常財務盈餘反應係數發生影響，實證結果發現異常財務盈餘確實可增加公司價值，且財務資產帳面值、營業資產帳面值、異常營業盈餘等亦與公司價值相關，惟未來異常財務盈餘持續性與未來異常營業盈餘持續性並不相同。然而，在將非稅成本與兩稅合一因素納入模式後，實證結果指出非稅成本愈大的公司，其異常財務盈餘係數愈小，間接證實異常財務盈餘與公司融資活動有關。同時，在其他條件不變情況下，由於營所稅已非公司費用而係股東綜所稅之預繳，因此實證結果也指出兩稅合一後公司異常財務盈餘對公司價值之提高，較兩稅合一前為小，且有效稅率愈高的公司，其異常財務盈餘對公司價值的提高也愈小。此種結果也間接證實兩稅合一會使股東可扣抵稅額的租稅利益增加，進而減少舉債的租稅誘因。

This paper extends Feltham-Ohlson (1995), Harris ＆ Kemsley (1999) and Zeng's (2001) residual income models by adding corporate tax and shareholders tax to form the tax-adjusted market valuation model, and suggests that the market value of a firm is a function of book value and after-tax earnings. Due to tax deductibility on interest expense, financial assets can generate non-zero abnormal financial earnings, and thus enhance the market value of a firm. We expect, under the tax-adjusted framework, that debt-financing performance has impacts on earnings response coefficient of abnormal financial earnings. Our empirical results indicate that abnormal financial earnings certainly can increase firm market value and that financial assets book value, operating assets book value and abnormal operating earnings are related to firm value. But, earnings persistence of abnormal financial earnings and that of abnormal operating earnings are different.However, after incorporating non-tax cost and integrated taxes system into the tax-adjusted market valuation model, we find that abnormal financial earnings response coefficient is smaller for firms with relatively higher non-tax cost. Such result indirectly confirms the influence of debt-financing activities on abnormal financial earnings. In addition, ceteris paribus, since corporate income tax is no longer an operating expense for an enterprise, instead, it can be used to offset shareholders' individual income taxes. These empirical results also suggest that abnormal financial earnings response coefficient after the enactment of 1998 integrated taxes system in Taiwan is lower than that before 1998, and abnormal financial earnings response coefficient is lower for firms with relatively higher effective tax rate either before or after 1998. Such finding also indirectly confirms firms with greater imputation tax credit will tend to have lower debt under integrated taxessystem.