Oral dosage forms are mostly preferred route for administering drugs to patient. But due to the poor solubility many drug has limited used in oral administration. Solubility is a one of the significant factor which affects dissolution rate and bioavailability. Solid dispersion is an effective method of improving the dissolution rate of poorly water soluble drugs and hence its bioavailability. In this study will focus on various methods of solid dispersion preparation, their advantages and major challenges