Abstract: In order to carry out the functions of trade non-repudiation and privacy protection of E-commerce, the non-repudiation protocol NRP3 is improved. Based on the protocol NRP3, this paper presents the E-Commerce prototype system with functions of trade non-repudiation and privacy protection. By testing, it shows that the protocol NRP3 can satisfy the requirements of E-commerce application, and effectively provide nonrepudiation and privacy protection for clients and merchants.