Abstract: Disclosed is a silicon-based anode active material for a lithium secondary battery. The silicon-based anode active material imparts high capacity and high power to the lithium secondary battery, can be used for a long time, and has good thermal stability. Also disclosed is a method for preparing the silicon-based anode active material. The method includes (A) binding metal oxide particles to the entire surface of silicon particles or portions thereof to form a silicon-metal oxide composite, (B) coating the surface of the silicon-metal oxide composite with a polymeric material to form a silicon-metal oxide-polymeric material composite, and (C) heat treating the silicon-metal oxide-polymeric material composite under an inert gas atmosphere to convert the coated polymeric material layer into a carbon coating layer.