Abstract: OBJECTIVE To study effect of L-proline on the crystallization and dissolution of curcumin， to explore the mechanism of the synergistic substance to improve the solubility of the insoluble active component of traditional Chinese medicine， and to find a method to solve the problem of poor oral bioavailability of traditional Chinese medicine. METHODS The curcumin/L-proline samples were prepared by grinding method and solution crystallization method， respectively. The structure was characterized by differential scanning calorimetry (DSC)， X-ray diffraction (XRD)， fourier-to-infrared (FTIR) and scanning electron microscopy (SEM)， and the content and solubility were determined by high performance liquid chromatography(HPLC). RESULTS In the presence of L-proline， the crystal form and the crystal habit of curcumin changed in different degrees. Compared with the raw curcumin，the solubility and dissolution rate of the samples were higher. CONCLUSION L- proline can affect the crystal shape and crystal habit of curcumin，L-proline/curcumin cocrystal was formed， and the solubility of cocrystal is obviously improved.