The invention provides a composite transition metal oxide precursor, a preparing method thereof and an anode active material. The composite transition metal oxide precursor is a composite transition metal oxide containing nickel (Ni) and a transition metal. A crystal structure has a cubic system or a structure with a cubic and spinel mixed together. By use of the composite transition metal oxide precursor with excellent structural stability, keeping and operability of a precursor stage is improved, an anode active material using the abovementioned precursor is easy to synthesize, and an anode active material for a secondary battery which has long-term reliability and excellent electrochemical properties can be provided.