Abstract: In order to investigate the effect of different contents of rare earth element Y on the mechanical properties of titanium alloy TC4, TC4-Y titanium alloys with rare earth element Y contents of 0.3%, 0.6% and 0.9% are prepared by smelting technology. Then the density, hardness, tensile properties at room and high temperatures of TC4-Y titanium alloys are tested. The results show that the mechanical properties of TC4 titanium alloy are improved by adding rare earth Y. With the increase of Y element content, the density, hardness, strength and plasticity of the alloy increase first and then decrease. When the Y content is 0.3%, the hardness of TC4 titanium alloy is the highest. When the Y content is 0.6%, TC4 titanium alloy has the highest density and the best strength and plasticity. The grain size of TC4 titanium alloy decreases rapidly when Y is added. When the addition of Y is 0.6%, the mechanical properties of TC4 titanium alloy are the best.