Reexamination the scope of Personal Data in the Big Data era-Learn from Japan Personal information, considering it should be carefully handled under the vision of respecting the personality of an individual, shall be made subject to proper handling. But base on the Big data operation recently, people can collect, practical use, and analysis a large amount of personal data quickly. The results are used in medical search, marketing, or formulate government policies. Because it will pose a threat to personal privacy, because they are often the second use of personal data, the Individual can’t foresee the matter. Not only make the Individual feel uneasy, so that individuals may suffer the loss of rights and interests also. How to make sure that Individuals are in control of their personal data, on the other hand, by operation of the big data, personal data can be utilized in industrial innovation, medical advance, or the development of national polices. That is the most important issue about Personal Data Protection Act in recent year, It’s also an important motivation for Japan to amend Act on the Protection of Personal Information in 2015. This article is based on the Japanese Act on the Protection of Personal Information in 2015, to describe and analysis individual identification code, that Is a new type of personal date as id-card number etc, is recognized as a Personal data to protected by law. And introduced the Anonymously processed information of anonymous data, explain its processing methods, and the legal obligations which personal information handling business operator should comply with. The final review Personal Data Protection Act of our country, pointing out the inadequacies of the regulations, and the suggestion when amending the law.