OBJECTIVE：To prepare Cheler ythrine （CHE） solid dispe rsion （SD），optimize the formulation technology ， characterize its preparation and investigate its in vitro antioxidant activity. METHODS ：The content of CHE in SD was determined by UV spectrophotometry. Based on single factor tests ，using the product yield as index ，using preparation method ，carrier material type，carrier material proportion （drug-carrier material mass ratio ）as factors ，the formulation technology of SD was optimized by L（9 34）orthogonal test and validated. Based on solubility and accumulative dissolution determination ，the product was characterized with thermal analyssis ，X-ray diffraction and scanning electron microscope. Using ascorbic acid as positive control ，in vitro antioxidant activity of the product was determined by DPPH method. RESULTS ：The linear range of CHE was 2.4-5.6 μg/mL； quantitation limit and detection limit were 0.066 9，0.022 1 μg/mL；RSDs of precision ，stability and reproducibility tests were all lower than 2％；recoveries were 97.50％-99.25％（RSD＜1％， n＝3）. The optimal preparation technology included using PEG 6000 as carrier material ，carrier material ratio of 1 ∶ 3， prepared by solvent method. Three batches of CHE-PEG-SD were prepared. Verification test results showed that the 话：0539-80311889。E-mail：zhenshengao@163.com accumulative dissolution of CHE-PEG-SD was （61.72 ± 0.67）％ at 15 min，and the yield was （99.04±0.83）％. The results of characterization showed that after CHE-PEG-SD prepared ， its solubility （3.725 mg/mL）and accumulative dissolution （61.25％，15 min）were higher than CHE raw material [ 0.098 mg/mL， 6.24％（180 min）]. The endothermic peak and crystal absorption peak moved or even disappeared compared with raw material and the carrier material ，and CHE was uniformly dispersed in the carrier material as an amorphous state. Results of in vitro antioxidation test showed that different concentration of CHE-PEG-SD showed certain ability of DPPH free radical scavenging ，and the IC 50 was 0.124 mg/mL，higher than 0.041 mg/mL of ascorbic acid. CONCLUSIONS ：Established content determination method is simple and accurate. The optimal SD formulation technology is stable and feasible. The solubility of prepared CHE-PEG-SD increases，and the dissolution in vitro increases，showing certain in vitro oxidation resistance.