Abstract: Based on the improving structure of Gabor, a fast sparse decomposition algorithm is presented in this paper. According to the characteristic of Gabor, the phase of Gabor atom is varied with the variations of shift factor and frequency factor by theoretical derivation, and the range of the variations includes the variation of phase factor in Gabor atom. Therefore the phase factor is not need to be used during sparse decomposition, then the computation complexity is decreased, and sparse decomposition is quickened.Simulation results show that the computational efficiency of the proposed algorithm is about 11.7 times as high as that of using Gabor atoms that its phase factor is not gotten rid of, and the algorithm has not the defect of certain randomness from intelligent computation.