A　new　simple　and　effective　approach　completely　based　on　the　physical　theory　is　proposed　for　protein　design.　Compared　with　the　similar　works,　the　algorithm　saves　a　vast　deal　of　trouble　in　exploring　sequence　space.　The　method　is　an　improvement　over　previous　works.　The　design　procedure　was　tested　on　three　lattice　models　in　two　dimensions　and　the　successful　results　have　been　obtained.　The　method　can　be　readily　implemented　for　three-dimensional　off-lattice　models　of　real　proteins.