Abstract: The microalloying action has been investigated by adding ppm order RE in spraying materials. The test results show that RE can be solid-soluted in the matrix of the spray welding layers and can form an intermetallic phase(Ce-Fe). Most of the RE additions exist in the inteusion as RE silicides and RE oxides. The addition cf RE affects the nucleation, growth and distribution of the hard phase in the matrix and the microalloying action has been achieved consquently.