According to the spatial energy aggregation properties of wavelet transform,a new wavelet image compression algorithm based on energy-tree coding is proposed.On the basis of discrete wavelet transform,the algorithm respectively constructs hierarchical energy-trees of all the high frequency sub-bands by direct measures of local energy,and equivalently represents sub-band coefficients with the parameters of its total energy and energy angles of all the levels.In light of the given compression ratio,select an appropriate cost function to construct the optimal energy-trees,then digitize and code their parameters,and the wavelet image compression is completed with adaptive bitrate allocating.Experimental results show that the proposed algorithm is of better compressing performance with simple implementation compared to many state-of-art wavelet coders.