本研究以1999年至2005年中國上市公司財務資料，探討影響中國上市公司有效稅率之決定因素。本文的實證結果發現中國全體上市公司樣本的平均有效稅率僅達14.14%，遠低於中國稅法規定33%的名目稅率，顯示上市公司普遍享有區域及行業優渥的租稅優惠，實際所得稅負並不高。其中以海南市、上海市的有效稅率最低，而西部偏遠地區的有效稅率為最高，顯示區域間租稅負擔不均之現象。採掘業公司平均有效稅率高達25%，農林牧漁業及信息技術業的平均有效稅率在10%以下，也反映產業間的稅負分配受到政府產業發展的租稅獎勵政策之影響。此外，近年中國會計制度積極與國際會計準則趨同，企業依財會準則所計提之資產減損準備在稅務上不能列報扣除，使公司須繳納較高之有效稅率。 本研究也發現中國上市公司的股權結構與其有效稅率間具有顯著的相關性，國家持股比率較高者，租稅規劃意願低，有效稅率較高；而外資持股比率較高者及有發行B股或H股的公司，享有較多的租稅優惠及有較積極的租稅規劃傾向，有效稅率則較低。最後，本文也發現一些重要的中國企業特性、財稅差異項目與公司有效稅率關聯性之實證證據，中國上市公司的企業規模與有效稅率間，呈現正向關係，符合政治成本假說。獲利愈高的公司，其有效稅率也亦高。公司資本資產密度與財務槓桿的稅盾效果並不顯著，研究支出之投入與有效稅率呈負相關。營業費用比率較高之企業，受到稅法對於多項費用列報限額標準之影響，如罰款支出、贊助費、非公益、救濟性捐贈支出、廣告費、宣傳費、業務招待費以及職工薪金等，也有較高之有效稅率。企業獲配股利所得及依權益法認列的投資收益較多者，在稅法上毋須列入課稅所得之金額較高，故其有效稅率較低。上述中國上市公司的企業特性與有效稅率之關聯性，提供了中國企業經營的租稅成本深受中國會計、租稅制度、公司特性以及商業環境影響之實證證據。 / This study investigates the effects of Chinese accounting standards and tax system on the corporate effective tax rates (ETRs) of china listed companies. Despite that the statutory tax rate of China income tax law is 33%, we found the average ETR of China listed companies is only about 14.14% during our sample period spanning from 1999 to 2005, suggesting that most listed companies across various areas and industries may enjoy substantial tax incentives. The empirical results show that the companies in Shanghai and Hainan have lower average ETRs then those in other areas. Especially, the agriculture, forestry, herding, fishery industries and the information technology industries have the lowest average ETRs of below 10%, possibly due to that Chinese government provides substantial tax incentives for both industries. Further, to converge with the international accounting standards, China gradually phased-in the accounting for asset impairments in 1998 and 2001, requiring listed companies to recognize the impairment losses when the fair values of assets are below their book values. However, the unrealized asset impairment losses are not deductible in filing income tax returns, resulting in that firms reporting greater asset impairment losses in financial statements are more likely to bear higher ETRs, ceteris paribus. In addition, we also found there is a significant relationship between China companies’ ownership structure and corporate ETRs. Ceteris paribus, companies having greater state-shares are more likely to have greater ETRs while companies having greater foreign institute-shares and companies issuing B-shares or H-shares are more likely to have lower ETRs. Finally, we also documented evidence on the relationship between Chinese firms’ characteristics and corporate ETRs. Chinese large firms are more likely to have greater ETRs, supporing the political cost hypothesis. Due to several limitations on claiming operating expenses to be tax-deductible items, firms with greater operating expenses are more likely to have greater non-tax-deductible expenditures and hence tend to have higher ETRs. Finally, to alleviate double taxation on dividend income, dividend income received by the investment companies is tax-exempt to the extent that the invested companies have paid corporate income tax on the dividends distributed to the investment companies, and unrealized investment income accrued by the equity method is not taxable income to the investment companies until distributed to them. Consequently, firms having greater dividend income and investment income accrued by the equity method are more likely to have lower ETRs. Moreover we also find that the tax reform in 2002 make average ETRs increasing. The companies listing in Shenzhen Stock Exchange have lower average ETRs then those in Shanghai Stock Exchange. The results of this study provide empirical evidence on that the Chinese accounting standards and tax systems have a significant impact on the tax costs and distribution of tax burdens of Chinese listed companies.