When finite length signal is the input of QMF banks which are composed of the M-band orthogonal wavelet filter, the boundaries of reconstructed signal are not reconstructed perfectly. For boundary signals to be reconstructed perfectly, different type filters or methods are applied to them. In this paper, the design method of boundary filters which can be reconstructed the boundary signal perfectly was proposed, in case the dimension of M-band decomposed signal is the same as that of input signal. The boundary filters were designed using the perfect reconstruction condition of paraunitary matrix. In an application of subband coding of still image, the proposed boundary filters achieve better PSNR about 5% in reconstructed image than reflected method at the same bit rate.