Abstract: Red clay gravel bed in Guilin area attracts many attentions to its engineering-geological characteracteristics. But its genesis is still in controversy. In this paper a discussion is made on the engineering use of the red clay gravel bed. It can be used as natural foundation supporting low-story buildings or as filling of lowland,such as,ditch, pond, hallow and gully. If the bed is thick enough, its hard part can be used as support layer of pile foundation.