Abstract: Triangle expanding tree is introduced with its nodes arranged in sequential order and using double flags for representing vertex coordinates along with their topological connection.Special data structure utilizing the geometric coherence of connected nodes in the tree guarantees higher compression ratio and higher precision of shape representation.Furthermore,the presented method needs less storage space due to its ordered access to the linked vertices.As the connections and coordinates of model vertices can be decompressed simultaneously,it becomes possible to decompress and render in parallel, resulting in higher processing speed.Comparing with existing algorithms,this method has some obvious advantages such as higher precision of modeling,faster processing speed and higher compression ratio.