Abstract: The temperature-expansion diagrams of austenite continuous cooling were measured for the weld metal of 10CrNi5MoV steel at different cooling rate with Gleeble-3 500 simulator.Through expansion volume of different temperature the diagrams of austenite transformation kinetics were gained.Effect of cooling rete on austenite transformation were studied.The results show that the curves austenite transformation kinetics of the weld metal were “S” type at different cooling rate. The curves of transformation rate of austenite vs temperature showed a single peak at the cooling rate of 60 ℃/s、30 ℃/s or 15, the curves of transformation rate of austenite vs temperature bainite and granular bainite transformation twin peak at the cooling rate of 6 ℃/s.