On Chromatic-Choosable Of One Class Of Complete Multipartite Graphs

List coloring of graph has become one of the hottest researching points formany scientists in the world. In this paper, we study the chromatic-choosability ofgraphs on list coloring. A graph G is called chromatic-choosable if Ch(G) =χ(G).For the choosability of graphs, Ohba conjectured that every graph G with 2χ(G)+1or fewer vertices is chromatic-choosable in 2002. It is easy to see that Ohba'sconjecture holds if and only if it holds for complete multipartite graphs. The graphfor which Ohba's conjecture has been verified are some complete multipartitegraphs. In this paper, we show that graphs Ks+3,3*t,2*(k-s-2t-1),1*(t+s)￡t≥0; k≥s + 2t + 1; 2≤s≤5)are chromatic-choosable. Hence Ohba's conjecture holdsfor Ks+3,3*t,2*(k-s-2t-1),1-(t+s)￡t≥0; k≥s + 2t + 1; 2≤s≤5)and all k-chromaticsubgraphs of them.This paper includes five chapters: The first chapter is introduction, introducingthe phylogeny of graph theory, and the researching purpose and meanings of thispaper; The second chapter is preparative knowledge in which we give some infor-mation on graph and some concept of graph; In the third chapter, we introduce thecurrent situation and obtained consequence on chromatic-choosable research; Inthe forth chapter, we prove the chromatic number of one class of complete multi-partite, and verify Ohba's conjecture; In the last chapter, we sum up what we havedone in this paper.