Abstract: With the continuous development of the network technology, computer and network crimes tend to be more and more. The methods used by the criminals are diversified and the technology is higher and higher. In the judicial practice, it is very hard for the court to make judgment about whether the evidence concerning data electronic document has been tampered or not in the process of transmitting by network. However, the technology of electric signature can ensure that data electronic document will not be peeped at, stolen, tampered or being faked in the process of transmitting. Thus, electronic signature can be used as auxiliary evidence of data electronic document. According to the Law of Evidence, it is with practical significance to give electronic signature with legal validity and to guarantee its advantage, so as to provide base of law guarantee for the e-commerce.

Key words: electronic evidence, evidence of electronic signature, characteristics of evidence