Judicial Yuan Interpretation No. 705 associates with the Ministry of Finance orders prescribing the standard of assessment in tax declarations for the amount to be deducted for the donation of land, which do not comply with the principle of taxation by law of Article 19 of the Constitution. These administrative rules are not merely detailed or technical matters for the enforcement of Income Tax Law. Such matters shall be specified by a law or regulations having the clear authorization of a given law. In addition there are two conflicked present situations. Firstly, the postponement of eminent domain for the land reserved for public facilities and the private preexisting roads burdened with public easement, to persist the protection of people's property right to develop personality and to maintain dignity of people disclosed by Judicial Yuan Interpretation No. 400 make it legitimate to render the abovementioned land tax-deductible. Secondly, the tax saving planning of taxpayers through purchasing and then donating these land tremendously reduces Income Tax revenues. However utilizing purchasing cost as the basis to estimate the amount to be deducted for the donation of land is not fair and reasonable sufficiently. The amended draft of Article 17-4 of the Income Tax Law still not well protect people's property right and maintain their dignity. This thesis reveals using the existence of “property loss” and “special sacrifice” as the distinguished standard. Only when the taxpayers have the right to be compensated from land expropriation, can donate the land to have the tax deduction which equals to eminent domain compensation. Besids, the Land Expropriation Act 30 states: “The value of land reserved for public facilities in the urban planning area shall be compensated based on the average market value of its adjoining lands not reserved for public facilities.” It shall be refered to maintain the unitity of law and just compensation. For those people purchased then donated land for tax deduction, if there is no special sacrifice, declarating the amount according to the “government declared value” of the donated land shall be considered as the cases of over tax incentive and have the possibility of applying principle of substantive taxation. The suggestions of lowering the impact of finance are restricting the donated land must be received only by local government with expropriation obligation, limiting total receiving amount of donation per each year and deducting tax by installments.