The concept of constant supply of land in the economic literature being shown wrong, this paper uses new concept of nonconstant supply of land instead to investiagte the efficiency and the equity of land taxes. The author finds that an increase in the land value tax will decrease the excess burden and enhance the equity, but an increase in the land value increment tax will get the opposite results. However, the Republic of China have adopted the perverse policy, i.e., put heaviest taxes on land value increments but light taxation on land value. Therefore, reverse reforming current land taxation is suggested, namely. raising land value tax enough to get back the cost of the public goods and lowering the nominal land value increments tax rate to be same as that of the property income tax.