Abstract: Isothermal and temperature-gradient double tension tests have been conducted on 4 lots of low alloy high strength hull steels to study the correlation between crack arrest temperatures obtained in different temperature fields. Test results indicate that under the same main tensile stress, the value of temperature-gradient crack arrest temperature is higher than that of isothermal crack arrest temperature. The difference of these two temperatures increases linearly with the increase of main tensile stress and shows an approximately quadratic function relationship with the plate thickness. Test procedures of isothermal and temperature-gradient double tension tests have been analyzed from the perspective of energy balance and the main influencing factors including main tensile stress, nil-ductility transition temperature and plate thickness, on which basis, a correlation expression is proposed and its validity is identified by test data of low alloy high strength hull steels with thickness no more than 80 mm.