Abstract: The diffusivity and permeability of hydrogen in Inconel 690 alloy were investigated using an ultra-high vacuum gaseous permeation technique.The curves of hydrogen permeation of 690 alloy materials with different thickness over the temperature range of 300~500℃ were gained,and the effects of thickness of 690 alloy on the hydrogen diffusivity（D） and permeability（P） were discussed.The results indicated that the diffusivity and permeability of hydrogen with the change of temperature in Inconel 690 alloy were conformed to Arrhenius relationship in the extent experimental temperature range.The hydrogen diffusivity increased with the increasing of samples thickness and equal to the actual body diffusivity of Inconel 690 alloy,and the hydrogen permeability kept constant with the increasing of sample thickness.