In the age of digital revolution, so called third industrial revolution. we enjoy the convenience of digital devices such as computers, smart phones, etc. Digital technology is inseperable from our everyday life any more. The proportion of digital information from all information in the world is estimated at over 95%. With this trends, digital information plays an important role to prove criminal facts and digital evidence which is presented to the court in the criminal proceedings has increased rapidly. Therefore, digital forensic continues to increase its importance. Nowadays criminal investigaion is impossible without computer forensic or digital forensic. However, legal or institutional bases for digital evidence is not sufficient. So it is questionable whether we are ready for dealing with digital evidence in the criminal procedure. So far, most researches have been concentrated on the procedural legality of search and seizure of digital evidence. The issue of identification or integrity has been relatively less handled. Digital evidence is easy to forge, falsify, modify and delete, so it is hard to preserve the chain of custody. This is the reason why we should have interests in the integrity of digital evidence. This paper deals with the admissibility of digital evidence, inter alia, identification or integrity as the requirement of admissibility of evidence. It consists of 4 chapters. The main ideas lie in chapter 2 and chapter 3. Chapter 2 deals with the identification or integrity of digital evidence as the requirement of evidence. At first, the concept and characteristics of digital evidence are laid out and the conditions of admissibility of digital evidence are looked into. Next, the integrity as the requirement of admissibility of evidence are discussed in detail. Chapter 3 handles the methods to ensure the integrity of digital evidence. It is studied what kind of measures and process are to be taken for securing of identification or integrity of digital evidence, while law enforcement agencies such as police officers or prosecutors collect and preserve digital evidence. Subsequently, which way or process is desirable to confirm the identification. Several ways e.g. Manipulation Detection Code(MDC), Message Authentication Code(MAC), Public Key Infrastructure(PKI), and so forth have been suggested for securing the integrity of digital evidence. Each method has strengths and weaknesses. This paper proposes the combination of them. In this paper the issue of identification of digital evidence is dealt with roughly. To prove criminal facts truthfully and efficiently, the more studies on identification or integrity of digital should be made consistently.