Fracture toughness JIC and KIC tests were performed on A516 Gr70 carbon steel plate at the temperature ranging from -$160^{circ}C$ to $600^{circ}C$, and test results were analyzed according to ASTM E 813 and ASTM E 399. Unloading compliance J-integral tests were performed on 1TCT specimens. The relation between the $J_{IC}$ value and the test temperature was obtained. It was concluded that the temperature ranging from $-15^{circ}C$ to $600^{circ}C$ is the upper shelf region of ductile-brittle transition temperature, and in this temperature range, fracture toughness $J_{IC}$ values decreased with increasing temperature. The ductile brittle transition temperature of the material may be around $-30^{circ}C$. In the region near $-30^{circ}C$, the tendency of $J_{IC}$ to decrease with decreasing temperature was significant.