本文主要論點在於營利事業所得稅之課稅客體為「所得」，而發行股票超過票面金額之溢價為「資本公積」，並非「所得」，即非所得稅法中營利事業所得稅之課稅客體。雖人民有依法律納稅之義務，惟租稅之法律關係，必須以租稅法律主義為前提，課稅構成要件之法律規定必須從嚴解釋，既不能擴充法定之範圍，亦不容比附類似之事項或反面解釋。大法官會議解釋第315號及行政法院80年度判字第1015號判決，對於獎勵投資條例第25條、行政院56年12月7 日台經字第9494 號令及財政部56 年12 月10 日台財稅發字第13055 號令將發行股票超過票面金額之溢價認定是繳納營利事業所得稅之客體，顯然錯誤。
財政部雖於1992年1月13日修正營利事業所得稅查核準則第30條第4項規定「股份有限公司股票發行溢價為資本公積」非所得，不必課徵營利事業所得稅，惟此不僅造成法規命令與大法官會議釋字第315號之牴觸外，更使租稅法體系錯亂。

The main point of this study is trying to clarify that tax object of income tax refers to all incomes of profit-seeking enterprises, while the premium for issue of shares above par value as additional paid-in capital (capital reserve) is not regarded as income, exempted from the income taxation object. Although people are obliged to pay taxes as mandatory duty pursuant to Tax law, the relationship of tax law must be within the premise of tax legalism. All taxation elements shall strictly comply with sound interpretation and the interpretation shall not go beyond statutory scope of tax rules, regulations and laws. Similar or reverse interpretation should not be liberally or negatively invoked. The J. Y. interpretation No. 315 and the 1991 Administrative Court judgment NO.1015, the Encouragement of Investment Ordinance Article 25, the December 7 1967 Executive Yuan explanation No. 9494 and the December
10 1967 Ministry of Finance explanation No. 13055 all held that the premium for issue of shares above par value being identified as "income" subject to corporate income taxation, was apparently in error. In January 13 1992, although the Ministry of Finance amended the paragraph 4 of Article 30 of profit-seeking enterprise income tax auditing criteria indicating that "Co., Ltd. issue of share at premium as additional paid-in capital (capital reserve)" is non-income. Such criteria and rulings lead to significantly conflict with the tax regulations, laws and the J. Y. interpretation No. 315. As such, the criteria and rulings obviously place current taxation mechanism in disorder.