The present invention relates to an anode active material comprising transition metal-metaphosphate of formula 1 as follows: M(PO3)2 wherein M is any one, or a combination of at least two elements selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, Ru, Pd and Ag. The anode active material of the present invention is stable and has good conversion reactivity while comprising only transition metal and phosphoric acid without using lithium of which the cost is consistently increasing, and thereby is capable of enhancing capacity properties.