The near band edge emission of the tensile-strained m-plane ZnO film grown on (112)LaAlO 3 substrates shows abnormal low polarization degree ( ¼ 0:1). The temperature dependency of polarization degree clarifies the origins of different emission peaks. In tensile-strained m-plane ZnO, the [0001] polarized state is upper shifted and is overlapping with the [1120] polarized state. This phenomenon causes the abnormal low polarization degree and reveals the effect of strain on the emission anisotropy of m-plane ZnO.