Abstract: During daily testing in one plant, the impact toughness of multi furnace batches of 1Cr11Ni2W2MoV steel bars was found unqualified. To find the reasons for disqualification, analysis was carried out from the aspects of chemical composition and heat treatment regime, and the comparative tests were done. The results show that: the tempering temperature of heat treatment was the main factor affecting the impact toughness of 1Cr11Ni2W2MoV steel; the impact toughness of the 1Cr11Ni2W2MoV steel specimens was all qualified when the tempering temperature was 540-590℃; the impact toughness of some 1Cr11Ni2W2MoV steel specimens was not qualified when the tempering temperature was 660-710℃. The qualified rate of the material could be improved and the production schedule could be ensured by selecting tempering temperature as 540-590℃.