The solvent treatment of paclitaxel is a convenient method for controlling the morphologies of paclitaxel. Amorphous paclitaxel was simply made by dissolving paclitaxel in methylene chloride/methanol (98/2, v/v) and in relatively non-polar solvents (t-butyl methyl ether, pentane, acetonitrile/hexane (1/2, v/v), methylene chloride, chloroform). On the other hand, dihydrated paclitaxel (paclitaxel·2H₂O) was made by dissolving paclitaxel in a special polar solvent containing a small amount of water. However, when we used only methanol, we got mixed morphologies of paclitaxel made of both the dihydrated and amorphous forms. Their physicochemical properties were investigated by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). The initial water content of amorphous paclitaxel and dihydrated paclitaxel was determined for 0.65 wt% and 5.85 wt%, respectively. The hygroscopic property of dihydrated paclitaxel was very changeable in all given humidity (15, 60, 95 RH%) during storage. Dissolution profiles for paclitaxel showed that amorphous paclitaxel measured the highest solubility in water and its solubility held most stable during the measurements. The residual solvent could be reduced to the maximum allowed value (600 ppm for methylene chloride, 3,000 ppm for methanol) of guidance for the International Conference on Harmonization (ICH) by spray drying.