OBJECTIVE： To prepare insoluble anti-tumor drug-loading polymer micelles， and to increase inhibitive effect of insoluble anti-tumor drug. METHODS： Chitosan （CSO） and stearic acid （SA） were used to prepare blank micelles （CSO-SA）， then modified with mPEG and folic acid （FA） to prepare PEG-CSO-SA and FA-PEG-CSO-SA. Characteristic functional groups of CSO-SA， PEG-CSO-SA and FA-PEG-CSO-SA were detected by infrared spectroscopy. The morphology of micelles was observed by transmission electron microscopy. The particle size and Zeta potential of micelles were measured by laser particle size analyzer. Osthole （OST） was used as the model drug and drug-loading micelles （FA-PEG-CSO-SA/OST） were prepared by dialysis. MTT assay was used to detect the inhibitory rate of FA-PEG-CSO-SA， OST solution and FA-PEG-CSO-SA/OST to human liver cancer cell HepG2. Half inhibitory concentration （IC50） was calculated. RESULTS： FA-PEG-CSO-SA was successfully prepared. CSO-SA， PEG-CSO-SA， FA-PEG-CSO-SA were oval in shape； particle sizes were （96.01±5.99）， （112.93±1.06）， （216.01±4.76） nm （n＝3） and Zeta potentials were （39.30±1.75）， （38.03±2.91）， （15.17±2.10） mV （n＝3）， respectively. Encapsulation efficiency and drug-loading amount of OST in FA-PEG-CSO-SA were （84.47±2.07）％ and （16.01±0.90）％ （n＝3）， respectively. The inhibition rates of FA-PEG-CSO-SA to HepG2 cells were＜20％. IC50 of OST solution and FA-PEG-CSO-SA/OST to HepG2 cells were （62.08±5.21）， （27.49±0.50） μg/mL （n＝3）， respectively. CONCLUSIONS： Prepared FA-PEG-CSO-SA can significantly increase inhibitive effect of insoluble drug OST to HepG2 cells， and it is expected to become a new anti-tumor drug carrier.