Abstract: In order to study the elevated temperature mechanical properties of 12Cr1MoVG steel continuous casting billet,12Cr1MoVG steel was subjected to elevated temperature tensile test at different temperatures by a Gleeble-3500 simulator.The fracture morphology,tensile strength and section shrinkage were analyzed and calculated.Experimental results show that tensile strength of 12Cr1MoVG steel decreases with increasing temperature,and the reduction of area decreases firstly and then increases with the increase of temperature.At 800 ℃ tthe plastic is lowest,and the temperature range of low temperature brittle zone is 738～865 ℃.The temperature range of γ→α phase transition calculated by Thermal-calc thermodynamic software is 747～869 ℃,which is agreement with the experimental results.The samples with tensile temperature higher than 900 ℃ show plastic fractures.When the temperature is lower than the low temperature brittle zone,the presence of inclusions causes the dislocations pile-up and then become the source of cracks and cause transgranular and intergranular fracture.