`Taxation by statutory law` principle both in Korea and Japan is a sort of an offspring of the more general principle of `administration by statutory law`, which requires statutory law for the government to restrict on people`s liberty and property and also gives priority to the statutory law over the determination either by the administration or by the judiciary when both are in conflict. Both principles that a taxable event should be prescribed by statutory law and that such taxable event should be prescribed in definite and clear terms come from the common principle of `taxation by statutory law`. Historically viewed all those principles originated from the German `Grundsatz der Gesetzmaßigkeit des Besteuerung`, which means `principle of legal taxation` and is somehow different from `taxation by statutory law` in its nuance. The reason why the term `taxation by statutory law` rather than `principle of legal taxation` is used both countries may be found in their individual constitutions both of which have almost the same provision that `a tax and its tax rate should be stipulated by a statutory law`. Notwithstanding such historically common grounds found in the 3 countries, the term `taxation by statutory law` in both countries affect the administration and especially the judiciary to apply tax laws in a more conservative manner than in Germany that the legal forms and structures taxpayers construct are generally respected with only a few exceptions for the purpose of taxation. Such attitudes, although they have their own merits, have to be compromised in harmony with the `equality principle`, which nowadays requires a `substantial equality` and therefore gives apparently more room for the administration or the judiciary to disregard or reconstruct the legal relations taxpayers have built for the purpose of applying tax laws.