The static and dynamic mechanical properties of the 93WNiFe heavy alloy improved by adding rare earth elements of La and Ce with different contents have been studied in this paper. The results show that the mechanical properties, especially the dynamic mechanical properties, can be improved by the addition of a small amount of La and Ce for the tungsten alloy due to the reduction of the segregation of oxygen and sulfur at the interface between W grains and matrix and the reduction of the contiguity of W grains. The reasonable adding content of rare earth is 0.10%-0.15%.