The influences of the pressure,temperature and duration time of Hot Isostatic Pressing（HIP）on the ultimate tensile strength（UTS）of Ti2 AlNb casting samples were investigated.It is found that the influence of HIP pressure on the UTS of the Ti2 AlNb casting samples can be ignored while the plasticity can be improved greatly with the increase of HIP pressure.The microstructure with fine Ophases dispersed in B2 matrix can be obtained by the HIP treatment of Ti2 AlNb alloy at a temperature from1 040 ℃to 1 100℃for 3 h,and the samples exhibit high tensile strength.The UTS of Ti2 AlNb casting can be improved greatly by HIP at 1 040 ℃for 1.5 to 3 h,while the UTS of the samples is decreased when the duration of HIP is increased to 4 h.