The microstructure and precipitation characteristics of 22Cr-14W-2Mo superalloys added with various La contents have been studied by SEM, TEM and EDX. It is found that the carbides are refined by adding La. M_(23)C_6 carbides inside the grain in a diameter of 50 nm have a cube-cube orientation relationship with the matrix, and these precipitates on {111} planes align along orientation. Since the large dissolved La atom will be a barrier to atom diffusion, it leads to an inhibiting effect on the carbides growing. M_6C carbides are influenced by La-S phases. La-S phases formed in the center of M_6C seem to be the heterogeneous nucleus of M_6C to increase the nucleation ratio. It is also noticed that finer M_6C carbides precipitated on the {111} planes of the matrix are around large M_6C. The finer M_6C carbides are caused by the special absorption effect of La-S phases.