The tax evasion, which is the taxpayer's attempt to pay off the payment of his taxes and non-compliance, is a barrier to achieve one of the basic and basic goals in the financing of the treasury revenues sufficient to cover the general needs, at a time when the country suffers from financial difficulties and increase the need to invest in addition to the problems of indebtedness, this has made it necessary to focus on the tax and make it an essential source of treasury financing. Therefore, any attempt to avoid the negative effects of pollution of the environment necessitates the necessity of pricing and estimating the value of the external effects and introducing these values within the special or internal costs of the economic unit. Partly and nationally, the external cost of pollution is the amount of increased and growing losses to society or the national economy as a result of environmental pollution. Tax evasion is a serious phenomenon that affects the public treasury, where countries miss a significant part of the financial resources. This results in the failure of the state to make public expenditure to the fullest extent. Hence, it is possible to identify the problem and questions of the study. Therefore, the researcher decided to clarify the real dimensions of this phenomenon The positive tax plays on the economy and the preservation of the environment. Egypt has witnessed a sharp collision in the phenomenon of tax evasion, and if this study is to clarify the importance of the tax as a basic financial resource in any country especially in the Arab Republic of Egypt and the statement of the economic and environmental effects of tax evasion during the period from 2000 to 2010, During this period, and to indicate the impact of this phenomenon on the economy and the environment also to clarify ways and means to combat the phenomenon of tax evasion. The study included the concept and importance of taxation and its objectives and effects on development, and the importance of taxes in addressing economic and environmental problems through the general budget, to identify the tax evasion and its manifestations in terms of terms and forms and methods of tax evasion, and identify the most important reasons that lead to evasion of payment of tax, As well as the impact of tax evasion on the economy and the environment and explain how to deal with the use of modern trends and how to use tax policies in combating environmental pollution and reduce tax evasion. The study found that there is a significant statistical correlation between tax evasion and the effectiveness of the Egyptian tax system, as well as the existence of a significant statistical correlation between tax evasion and the reduction of pollution of the environment. The study reached the importance of granting all powers to the competent authority to protect the environment The implementation and implementation of environmental protection, and decentralized administrations to consider granting exemptions and tax incentives, as well as to monitor and verify the implementation of the grant or incentive for exemption .