We prepared using low molecular weight water-soluble chitosan nanoparticle loaded paclitaxel(WSC-NPT) and investigated the potential as a drug carrier which is able to accumulate in the tumor site. WSC-NPT was treated with sodium azid (NaN3) as an inhibitor of endocytosis process. As results, the antitumor activity of WSC-NPT treated with sodium azid didn't show but WSC-NPT was shown the high antitumor activity. Therefore, WSC-NPs modified with hydrophobic group will be useful anticancer agent carrier via receptor-mediated endocytosis.