The encoded bit streams of video transmitted in error-prone channel are vulnerable to transmission errors, which usually result in missing blocks at the decoder. In this paper, an efficient spatial error concealment method for video transmission is proposed. The missing blocks are classified into uniform blocks and edge blocks by using the edge information extracted from the surrounding correctly received blocks. For the missing blocks, which are uniform blocks, the error can be concealed by simple linear interpolation. For the missing blocks, which are edge blocks, the initial values of the missing blocks can be obtained by prediction based on gradient adaptive prediction (GAP). The maximum a posteriori (MAP) method is used to implement the optimization with the initial value of the missing block. The experimental results demonstrate that the proposed algorithm not only can obtain excellent image quality, but also can be applied for real-time video transmission because of low computational complexity.