A cathode active material and non-aqueous electrolyte secondary battery. The non-aqueous electrolyte secondary battery includes a positive electrode and a negative electrode which are electrochemically doped and dedoped with lithium; and an electrolyte disposed between the positive electrode and the negative electrode. The positive electrode contains a cathode active material including a mixture of: a first cathode active material represented by a general formula: LitCoMsO2 where M represents a metal, 0≦s≦0.03, and 0.05≦t≦1.15; and a second cathode active material represented by a general formula: LixNi(1-y-z)CoyMnzAaO2 where A represents a metal, 0.05≦x≦1.15, 0.15≦y+z≦0.70, 0.05≦z≦0.40, and 0≦a≦0.10.