The Executive Yuan checked through ' land tax law 34th revised the draft ' on August 29 , the 96th year of the Republic of China, basis should revise the draft, to already suitable ' once-in-a-lifetime ' private residence land used for preferential land owner of tax rate, selling the land used for private residence again, and the person who accords with relevant regulation terms, can be once again suitable and private land used for preferential 10% of the lessons of tax rate of residence seek the land value increment tax. What influence will be there to fiscal revenues , society's fair , the economic efficiency and the tax administration this research is implementation probing into this policy through the questionnaire way? This research real example result is done into the following conclusion, first: Keep current " once-in-a-lifetime " private residence preferential tax rate and " purchase the refund of tax outside again ", revise and enlarge the preferential measure of relaxing " not restricting once-in-a-lifetime ", hide the considering of loss of tax revenues after implementing. Second: Relax personal preferential measure that house " not restricting once-in-a-lifetime ", must stipulate the condition " in 5 years before selling " among them, do not have for using or hiring out", will cause the persons who will use by oneself with for opening or tax among the lessor to donate and bear unfairly, and apt to give birth to and seek and receive both sides to dispute , increase the puzzlement of administrative litigation in vain. Third: Relax the preferential measure " not restricting once-in-a-lifetime " in the private residence , will be counted more largly and relatively have the ability to change the room because of the house level ground which the high income person has, it is relatively large and can be lightenned the tax interests of donating the burden. The house level ground that the low income person has is counted smaller and relatively has no ability to change the room, and get the unfairness phenomenon with less interests of lightenning taxes and donating the burden. Fourth: Relax the preferential measure " not restricting once-in-a-lifetime " in the private residence , will improve general people and change the will which will purchase the new room. The fifth: Relax the preferential measure " not restricting once-in-a-lifetime " in the private residence, equate government's tax subsidy to the person who sells private residence, will cause the improper disposition of resources , produce meaningless losses of the society.