Abstract: TC11 and TC17 titanium alloy usually used in aero engine blisk were welded with linear friction welding, the microstructures and element distribution were analyzed and tested by metallographic and electron probe, respectively.The temperature during the welding process was also measured.Results showed when the other parameters are constant, the width of TC17 thermal mechanical affected zone increases with the amplitude decreases, and microstructures of thermal mechanical affected zone at both sides are elongated along the stress direction and the nugget zone is composed of dynamic recrystallized grains.Cr distribution distance was farther when the amplitude at a higher value.The temperature measured results showed the maximum temperature can be up to 1 200℃ which exceeds the titanium beta transformation.