Poorly water-soluble drug, Raloxifene HCl, is a selective estrogen receptor modulator(SERM) and is currently being used for prevention of osteoporosis in postmenopausal women. We prepared solid dispersion with hydrophilic polymer, polyvinylpyrrolidone(PVP), and surfactant, Poloxamer 407, to improve the solubility of drug. Characterization of raloxifene HCl solid dispersion analyzed by scanning electron microscope(SEM) and Fourier transform infrared spectrometry(FT-IR). SEM and FT-IR were found that raloxifene HCl is amorphous and hydrogen bonding between drug and polymer in solid dispersion. The in vitro release behavior of solid dispersion presented at simulated gastric fluid(pH 1.2) and simulated intestinal fluid(pH 6.8). The dissolution rate of raloxifene HCl was dramatically higher than commercial drug(Evista(R)). This studies suggest that this solid dispersion system improved the bioavailability of poorly water-soluble drug, such as raloxifene HCl.