Abstract: Based on three dimensional transient heat conduction equation and elastic stress-strain equation,the temperature rise,distortion and equivalent stress distribution of white bijou window irradiated by high power annular beam(λ=(1.315)μm) are simulated using a three dimensional finite element model(FEM).The temperature rise,distortion and equivalent stress distribution of fluoride glass window induced by high power hollow rectangular laser beam(λ=3.8μm) are also simulated.Laser intensity spatial gradient and attenuation in window are considered in computational model.