Abstract: For the Internet videoconferencing applications, the rate of video flow to network must be controlled to prevent the network from congestion. A rate control scheme based on fuzzy logic control（FLC） is brought forward in this paper, in which the compressed code length is mapped into coefficients of quantizer used in the video coder to adjust the compressed code length of next video frame. By using this scheme, the code rate output of the coder can be reduced apparently on the basis of communication continuity and image quality guarantee to avoid the network congestion. The scheme of congestion avoidance is described in detail. Experimental results are shown and a simple performance evaluation is presented by comparing the scheme with relative congestion avoidance mechanism.