Tax investigation is a legal act of tax authority, in which the tax authority can exam tax returns and other documents of taxpayers and review if they are correct to their tax liabilities. It has not only functions of identifying the already done tax evasions but also functions of avoiding the potential tax evasions, by way of taxpayers' risk awareness. But from the viewpoint of tax investigation rate, the penalty system for tax evasions and fairness, the tax investigation system in Korea and its management could not be positively evaluated. on the other hand in the tax investigation the process neutrality must be kept in order to protect the taxpayers' right. So the Korean tax authority is confronted with difficult task. In this report we try to conclude the best possible policy guidelines for korean tax investigation system developed from the foreign and our own research results, and experience of foreign countries. The key policy implications of this report are summarized as follows. The tax investigation rate and the level of tax evasion penalties must be increased and upgraded. Above all the selection process of taxpayers for investigation must be done objectively. More information must be open about this selection process. And at last in order to protect the taxpayers' right in the process of tax investigation the individual steps of tax investigation must be coded in tax law.