Abstract: Based on reductive amination,dodecyl serum albumin (DSA) was synthesized and confirmed by ¹H NMR,elemental analysis and TG analysis.The CMC values of DSA were determined by fluorescence chromatography using pyrine as a probe.Paclitaxel (PTX) DSA micelles were prepared by dialysis and characterized by transmission electron microscope (TEM) and wide angle X-ray diffraction (WAXD).Then a series of indicators,including drug loading content (DLC),drug entrapment efficiency (DEE),particle size and Zeta potential were used to evaluate the effect of degree of substitution (DS) of alkyl segments of DSA on the drug loading capacity of PTX was investigated.The results indicated that DSA with a degree of substitution (DS) in the range of 7.72% to 31.71% was successfully synthesized and could self-assemble into micelles in water.PTX-DSA micelles exhibited excellent drug loading capacities for PTX with DLC and DEE high to (32.14± 4.13)% and (87.25±16.18)%,respectively,at the same time,the particle size and Zeta potential were (135.83±2.47) nm and -(31.07±0.51) mV,respectively.A spherical shape and a uniform size distribution were proved by TEM.WAXD of PTX-DSA micelles indicated that PTX was transferred to amorphous state after loading.It was concluded that the present DSA could be a potentially drug delivery system for insoluble anticancer drugs with improved drug loading content and stability.