Electronic evidence can be a product of different situations: Someone enters the data into a computer, the computer is performing a user's request or a computer automatically processes information. Therefore, Electronic evidence includes databases, operating systems, computer programs, computer generated models, electronic, audio records, and any type of information or instruction which is stored in computer memory or exchanged, processed, recovered or generated through computer or telecommunication systems. Authenticity or genuineness and admissibility of electronic evidences are subjects of this paper. We are discussing this subject by relying on the law of Iran, UNCITRAL Model Laws and Convention and related precedent from common law countries. Finally, it is suggested to the Iranian legislator to approve an Act to prohibit providing audio or image or video from others without their permission and without legal or judicial authorization, as well as non-admissibility of evidences provided with these illegal methods. In this way, citizenship rights will protect against the misuse of new technologies.