Abstract:In the paper,we extend the time-distance equation of multiple reflection waves produced by surface earthquake source in homogeneous single layer medium with inclined boundary plane in seismic exploration to any depth of the focus, put forward a time-distance equation group of multiple reflection waves in laterally homogeneous single layer medium in which the velocity is linear correlation with depth and whose boundary plane is slant, and discuss the,relatioiiship between the ground displacement and the epicentral distance for multiple reflection waves.