Abstract: Superresolution processing for acoustic holographic imaging, which is based on the finite region of the object distribution and utilizes the relation between elements of holographic matrix from it, is proposed to increase the resolution of the imaging system. The calculating formulas are derived and knowledge of obtaing the object distribution in actual calculation is discussed. The iteration of the method can be applied to increase indefinitely the resolution of the imaging system when noise is absent. Simulation with a computer is made, which proves the validity of the method. Finally, sensitivity of the method to noise is discussed, and the curves of output noise to signal ratio versus input noise to signal radio are given for some examples, which show that the method is particulaly suitable to small object distribution.