５０８Ⅲ钢是国际上核一级压力容器常用的材料，但国产５０８Ⅲ钢的疲劳和断裂性能尚未见报导。本文研究了国产５０８Ⅲ钢锻件的低周疲劳和动态断裂韧度。通过试验，得到了５０８Ⅲ钢的设计疲劳曲线和ｋＩｄ（ＴＲＴＮＤＴ）曲线，并与ＡＳＭＥ规范和ＲＣＣＭ规范相应的基准曲线进行了比较。结果表明，用于压水堆核电站反应堆压力容器的国产５０８Ⅲ钢的疲劳性能和动态断裂韧度符合ＡＳＭＥ和ＲＣＣＭ规范的要求。 508  Ⅲ steel is an international nuclear pressure vessel materials commonly used, but domestic 508  Ⅲ steel fatigue and fracture properties have not been reported. This paper studies the low cycle fatigue and dynamic fracture toughness of domestic 508  Ⅲ steel forgings. Through the experiment, the design fatigue curve and kId (TRTNDT) curves of 508Ⅲ steel were obtained and compared with the corresponding benchmark curves of ASME code and RCCM code. The results show that the fatigue properties and dynamic fracture toughness of domestic 508Ⅲ steel used in reactor pressure vessel of PWR meet the requirements of ASME and RCCM.