Abstract: OBJECTIVE To prepare and identify Murraya exotica L. leaves flavonoids hydroxypropyl-β-cyclodextrin inclusion complex(JK-HP-β-CD). The molar ratio between Murraya exotica L. leaves flavonoids and HP-β-CD as well as the thermodynamic constants in inclusion was also studied. METHODS The JK-HP-β-CD inclusion complex was prepared with solution-agitating method. Meanwhile, the inclusion complex was identified by differential scanning calorimetry, X-ray diffraction and infrared spectrometry, respectively. The molar ratio between host and guest molecules and the thermodynamic constants during the inclusion process were also investigated by phase solubility method. RESULTS A 1∶1 molar ratio inclusion complex of JK with HP-β-CD could be formed at 25, 35, 45℃. The phase diagram was AL type and the procedure of inclusion was a heat release process. CONCLUSION A 1∶1 molar ratio inclusion complex of JK with HP-β-CD could be formed spontaneously, which increased the solubility of JK in aqueous solution obviously.