Abstract. Polyethylene (PE) is indispensable materials in daily lives. To produce PE, the catalyst was needed in the reaction. Ziegler-Natta catalysts were mostly used which consisted of TiCl4 on the MgCl2 supports. Polyethylene particle was reported to replicate the shape of the catalyst particles or catalyst support particles. Therefore, the MgCl2 supports need to satisfy various requirements regarding particle morphology such as shape, particle size with uniform size distribution as well as the porosity. In this research, the preparation of MgCl2 particles from irregular shape of anhydrous MgCl2 by spray drying method was studied. The moisture was reported as the poison of the catalyst, so the unusual close loop spray drying under N2 conditions was used in this study. The different types of alcohol, ethanol, n-propanol and n-butanol as solvent which was used to dissolve MgCl2 before feeding through the spray drying on the particle properties were investigated. The amount of residual alcohol (alcoholic hydroxyl group content), morphology, specific surface area, porosity and crystallinity were determined by GC method, scanning electron microscope (SEM), N2 sorption analyzer and X-ray diffraction (XRD), respectively. The results revealed that spray drying process can produce the porous anhydrous MgCl 2 particles which have rough surface, higher porosity and lower crystallinity than original anhydrous MgCl2.