OBJECTIVE： To prepare Capsaicin solid dispersion， to optimize its formulation and characterize the dispersion. METHODS： Capsaicin solid dispersion was prepared by melting method using P188 or PEG4000 as carrier. Using 60 min accumulative dissolution rate in vitro as index， orthogonal test was used to optimize type of carrier， drug ratio and stirring time. Validation test was conducted. The stability of Capsaicin solid dispersion within 0， 30， 180 d was investigated at 40 ℃ under the relative humidity of 75％， and X-ray diffraction （XRD） was used to analyze whether there were peaks. Capsaicin solid dispersion was characterized by differential scanning calorimetry （DSC） and XRD. RESULTS： The optimized formula included P188-PEG4000 as carrier， capsaicin-P188-PEG 4000 mass ratio of 1 ∶ 5 ∶ 3， stirring for 20 min. Accumulative dissolution rate in vitro of Capsaicin solid dispersion was 84.6％ within 60 min （n＝3）， and the preparation kept stable within 180 d [RSD of content was 3％ （n＝3）； XRD showed that there was no peak]. The phase characteristics showed that capsaicin was highly dispersed in the amorphous or molecular state in carrier. CONCLUSIONS： The optimized technology can be used to prepare Capsaicin solid dispersion， and improves more than 80％ dissolution rate in vitro at 60 min. It is stable， simple and feasible.