The　entanglement　of　formation　for　a　class　of　high-dimensional　quantum　mixed　states　is　investigated.　A　special　kind　of　D-computable　states　is　defined　and　the　lower　bound　of　entanglement　of　formation　for　a　large　class　of　density　matrices　whose　decompositions　lie　in　these　D-computable　quantum　states　is　obtained.　Moreover　we　present　a　kind　of　construction　for　this　special　state　which　is　defined　by　a　class　of　special　matrices　with　two　non-zero　different　eigenvalues　and　the　other　eigenvalues　are　zero.　Making　use　of　the　D-computable　we　construct　a　class　of　bound　entangled　states.