To developed chitosan based Paclitaxel carrier, chitosan oligosaccharide (COS) were chemically modified with hydrophobic group of Balic acid (Deoxycholic acid and Lithocholic acid.). The physicochemical properties of the BA-conjugated COSs (CDs, CLs) were investigated by using 1H-NMR. dynamic light scatterign and spectrofluorophotometer. CBs nanoparticles were prepared by dialysis method. Paclitaxel-loaded CBs nanoparticles(DBs-Tex) were invesrigated by 1H-NMR. dynamic light scattering measurements, The CBs-Tex was investigated to pharmaceutical application as a Paclitaxel carrier.