Provided are an anode active material for a lithium secondary battery, and an anode composition and a lithium secondary battery including the anode active material. Silicon secondary particles, in which amorphous silicon primary particles and crystalline silicon primary particles are agglomerated, are used as an anode active material. The structural characteristics and internal pores of the silicon secondary particles act as a buffer for a volumetric change of particles, leading to a decrease in the volumetric expansion of an active material during charging and discharging. Accordingly, pulverization of silicon particles may be prevented, and ultimately, even when a charge and discharge cycle is repeatedly performed, the capacity is maintained, and thus, cycle lifespan characteristics are substantially improved.