Barium sulfate particles with average size of 16 urn and 203 nm were successfully synthesized by precipitation method at 25 degrees C. The characterization of BaSO4 particles were performed by X-ray diffraction (XRD), transmission electron microscopy (TEM). It was found that the selected reaction conditions played an important role in controlling the size of particles. The difference in morphology of BaSO4 particles mainly depends on the different additives during the precipitation process.