It requires an enormous amount of server and network bandwidth resources for providing real-time video streams to a large number of clients. And when using variable-bit-rate (VBR) encoded streams, frequent traffic bursts of bit rate have high variability for resource requirements. In this paper, we propose a smoothing of prefix caching and data sharing (S-PCDS) scheme based on the proxy caching, which can assist in smoothing operation for VBR encoded streams and reduce the start-up delay of users, through caching video prefix in the proxy. It can share the data in the buffer of proxy through interval caching which size is determined dynamically according to the current request distribution. With S-PCDS, the peak requirements of the resources can be reduced for VBR stream, the major of requests can share the data in the buffer, utility of the resource can be improved for the proxy, and the resource consumption can be minimized for the media server and back-bone network bandwidth. These are proved by comparing with several existing methods experimentally.