Experiment of warm laser shock peening (WLSP) of AZ80-T6 magnesium alloy at room temperature to 300 ℃ is carried out using Nd: glass laser. The results show that WLSP has obvious warm strengthening effect and generates higher residual compressive stress compared with LSP at room temperature. Surface compressive residual stress (-150 MPa) and micro-hardness get to the highest value at 150 ℃. Micro-hardness is improved by 35.8% compared with the substrate, showing the best warm strengthening effect. While the surface micro-hardness tends to be a stable value ranging from 122.1 to 119.1 HV at 150 ℃~250 ℃, exhibiting a good thermal stability. The three dimensional (3D) profile, surface morphology and surface roughness of the laser shocked craters at different temperatures are analyzed and discussed.