Abstract：Objective：To discuss the rules of composing prescription and administration of LI Fazhi treating femoral head necrosis in AIDS patients. Methods：A total of 353 outpatient prescriptions of LI treating femoral head necrosis due to AIDS were collected and arranged. The distributions of efficacies， meridian entry， four qi and five flavors of Chinese herbal medicines used in the prescriptions were counted and analyzed. Results：Among all Chinese herbal medicines used in the prescriptions， deficiency- supplementing medicine accounted for 39.56% ， which was the highest； the nature of most medicines was warm，accounting for 47.69%；the flavor of most medicines was sweet，accounting for 39.19%；as for the meridian entry of these medicines，the spleen meridian and the liver meridian were the most，accounting for 25.96% and 25.23% respectively，and the frequency of medicines for the spleen，the liver，the heart and the lung meridian was 89.13%. Conclusion： The treatment of LI Fazhi treating femoral head necrosis due to AIDS focuses on the care of healthy qi， nourishing the stomach and protecting the liver，and defending against pathogenic qi by healthy qi. Besides，LI is good at adding Chinese medicine with anti-AIDS effect discovered in modern medicine to the treatment.