A sputtering target for forming a high strength optical recording medium protection film is provided by sintering a mixed powdery material having a formula composition containing, in mol %, a zirconium oxide or a hafnium oxide of 10-70%, a silicon dioxide of 50% or less (not including 0%), and yttrium oxide of 0.1-8.4%, if necessary, and aluminum oxide, lanthanum oxide or indium oxide and an unavoidable impurities for the rest. A target base material has a structure wherein a composite oxide phase having a composition of Al6Si2O13 or La2SiO5 or In2Si2O7 is generated.