Objective To construct oligomeric hyaluronic acid(5 KDa)-modified ellagic acid-loaded liposomes(EA-HA-L)to improve the aqueous solubility,in vitro transdermal effect and whitening activity of ellagic acid.Methods Oligomeric hyaluronic acid-modified cholesterol(HA-Chol)was prepared by esterification reaction and structurally characterized by FTIR and 1H NMR;Oligomeric hyaluronic acid-modified ellagic acid-loaded liposomes were prepared by film dispersion-ultrasound method,and the prescribing process was optimized by Box-Behnken design-response surface method,and the particle sizes,the polydispersity index(PDI),zeta potential and encapsulation rate of liposomes under the optimal prescribing process were determined;the difference in solubility between EA-HA-L and free EA was evaluated;in vitro transdermal effect of liposomes were investigated using rat abdominal skin;inhibitory effect on tyrosinase and intracellular tyrosinase in mouse melanoma cells(B16-F10)was surveyed via dopa oxidation method.Results HA-Chol was synthesized and characterized;the optimized prescription process was mass ratio of 10:1 for soy phospholipids to HA-Chol,lipid-drug ratio of 40:1,hydration temperature of 30℃,hydration time of 60 min,ultrasound intensity of 35％,ultrasound time of 21 min,and the particle size of EA-HA-L produced under the optimized prescription process was(140.30±1.30)nm,PDI was(0.29±0.01),the encapsulation rate of ellagic acid was 91.16％±3.06％,and the zeta potential was(-5.67±0.09)mV;after EA was encapsulated by liposomes,the solubility of EA in water increased by about 40-fold;the cumulative transdermal amount of EA-HA-L was 46.98±2.17 μg·cm-2 in 24 h,and the intradermal retention was 66.15±0.61 μg·cm-2,which was 1.72 times higher than that of free EA(P<0.0001)and 1.23 times higher than plain liposome(EA-L)(P<0.01);and the tyrosinase inhibitory activity of EA-HA-L was higher than that of both free EA and EA-L in the EA concentration range of 50-400 μg·mL-1.Conclusion Oligomeric hyaluronic acid-modified ellagic acid-loaded liposomes with small particle size and high encapsulation rate were successfully prepared.EA-HA-L significantly improved the water solubility of EA and possessed better transdermal effect and stronger whitening activity than free EA and EA-L.