An image coding method is introduced in the field of image engineering which is a new and efficient image coding technique i.e. Embedded zero-tree wavelet EZW image coding. First, the course of evolvement from sub-band coding to wavelet coding, including multi-resolution analysis and filter bank on orthonormal wavelet bases is described, and then the wavelet technique for image decomposition and the fundamentals on EZW coding. Emphasis on detailed analysis and illustration of EZW algorithm is given, including zero-tree, scanning fashion and the approach in implementing steps. Finally contents mentioned above are summarized.