The article discusses the conception of the reform of the Polish tax system. The author stresses the need to correlate the tax system with the principles of market economy and tax standards of the European Community and the significance of tax system for carrying out the socio-economic program. The core of the tax system reform is income tax, corporate tax and value added tax. The article presents basic postulates concerning the construction of these three taxes. Main attention is been paid to income tax, due to fiscal significance of this tax and the possibilities of its impact. The author discusses also social elements of income tax, for this issue is often neglected in discussions. As to corporate tax, the need of its integration...