A Web server makes use of the HTTP(Hyper Text Transfer Protocol) to communicate with a client. The HTTP is a stateless protocol; the server does not maintain any state information for ongoing interactions with the client. Therefore, the HTTP inevitably requires additional overhead as repeating data key-in to user for continuing communications. This overhead in Web environment can be resolved by the cookie technologies. However, the cookie is usually unsecured due to the clear-text to transfer on the network and to store in the file. That is, information in the cookie is easy to exposure, copy, and even change. In this paper, we propose a secure cookie mechanism appropriate to Web environment, and then present a design and implement of secure Web system based on the scheme. The Web system can be used to any web environment. It also provides some security services, such as confidentiality, authentication, integrity.