Abstract: Using poly (vinylpyrrolidone) as a carrier, solid dispersions of tanshinone were prepared by spray drying method. The solubility of the solid dispersions was detected. X Ray powder diffractometer, scanning electron microscope, IR spectrometer and UV VIS spectrophotometer were used to investigate the physical and chemical properties of the solid dispersions. The results showed that the solubility of solid dispersions was significantly increased than that of the Tanshinone and the mixtures of tanshinone and carrier. Tanshinone was present exited as ultrafine crystalline or molecular form in solid dispersions. There was no chemical reaction between tanshinone and the carrier.