A method and apparatus for restoring an occluded window in application sharing. The method includes the steps of: detecting whether an unshared window occludes part of all of a shared window; making the unshared window semitransparent by an alpha blending operation in response to detecting an unshared window that occludes part or all of a shared window; changing the value of the alpha factor in the alpha blending operation, thus obtaining two alpha blended images; and restoring the occluded shared window by using the two alpha blended images.