The thermosensitive micelles based on the two series of cholesteryl-modified hydroxypropyl cellulose (series 1 and 2, respectively) were used as a promising drug carrier. The polymers 1a and 2a with side chain substitution degrees D Chol = 0.7 and 2.1 mol% were selected for micelle preparation, respectively. Polymeric micelles were prepared by the co-solvent evaporation method. The aqueous self-assembly of the polymers was studied using fluorescence analysis and transmission electron microscopy (TEM). The critical micelle concentrations (CMCs) values of the various D Chol of polymers were evaluated in the range of ca. 0.13–0.29 g/L which decreased with the increase of D Chol in both series. Furthermore, the CMC values displayed a downtrend profile, with increasing the temperature. The polymer 1a with less D Chol had lower CMC than that of polymer 2a. By using the naproxen as a hydrophobic model drug, the drug-loaded micelles were prepared. The TEM image of naproxen-loaded micelles of polymer 1a with 40 % drug-loading efficiency and 8 % loading capacity showed that micelles were regularly spherical in shape with a mean diameter of 70 nm. The unmodified HPC exhibited a lower critical solution temperature (LCST) of more than 41 °C in water, while polymeric micelles in aqueous solution presented an LCST of 38.7 °C. A drug release study was performed by dialysis method in phosphate-buffered solution at 25, 37 and 40 °C, respectively. The release kinetics of naproxen from the polymeric micelles revealed a thermosensitivity, since its release rate was higher at 40 °C than at 25 °C.