Abstract: The contrast studies of static tensile strength and fatigue life of base metal and laser welded (first focusing welding and then defocusing welding) TC4 titanium alloy samples were carried out by quasi-static tension and fatigue tests,and then got the static tensile strength,the S-N curve of median fatigue life,P-S-N curve of 95% safety fatigue life and the median and safety fatigue strengths at the 106 cycles . The results show that,comparing with the base metal,though the laser welding sample own higher tensile strength,their fatigue strength greatly reduced.