Land transaction approval system is that the lands which are to be developed are designated as the zone of land transaction approval and only transaction appropriate to the purpose of land use can be approved and the ownership of land can be transferred, in order to prevent real estate speculation and increasing of land price. Otherwise the prospect at the time of legislation, the effectiveness of the system itself have diminished, because betray of trust against land double-sale and violation against Act on Special Measures for Registration of Real Estate by false application for registration of real estate, ect can not be punished in criminal within zone of land transaction approval, as a result that court have applied the principal of "nulla poena sine lege" strictly to relating criminal case. In view of relating to failure of criminal effectiveness and prevent speculation forehand, the doctrine of making a denial to not only real right validity but also claim validity of the transactions under no approval of competent authorities is very significant. If the claim validity of them is recognized, there will happen frequent land transaction or speculation in way to preserve the qualification of vendee through provisional registration and resale it, On the side of civil law principle otherwise crime precedents, land double-sale within zone of land transaction approval should be determinate void as anti-social actions, Recently instead of preserving and resaling claim position of vendee by provisional registration, there have been mostly abused trust registration in way of which vendee in substance become beneficiary prior to other credits and land ownerships are transferred to beneficiary or person whom he/she will specify in order to secure claim effect of land transaction under no approval by evading or circumventing law. As this kind of trust must be typical evasive trust which is prohibited by Trust Act article sixth, the claim effect of this kind of land trusts under no approval should be also denied by extension of principal in which even claim effect of land transactions under no approval within zone of land transaction approval should be denied.