The inclusion complexation behavior of scutellarein (SCUE) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) has been investigated in both solution and in the solid state. SCUE/HP-β-CD solid system was prepared by suspension method. The formation of SCUE/HP-β-CD complex in aqueous solution was demonstrated by fluorescence spectroscopy, and the Job plot showed a maximum at a molar fraction of 0.5, indicating 1:1 inclusion complexation between SCUE and HP-β-CD. However, SCUE/HP-β-CD inclusion complex was characterized by means of XRD, DSC, (1)H, and two-dimensional NMR. Through the complexation between HP-β-CD and SCUE, the water solubility and antitumor activity of SCUE were obviously increased. This satisfactory water solubility and high antitumor activity of the SCUE/HP-β-CD complex will be potentially useful for its application on human colon cancer chemotherapies.