Effects of electromagnetic stirring on the microstructures of the laser cladding WC-CO based layers are studied. Both experimental and theoretical analysis indicate that the microstructures of the laser cladding layers under electromagnetic stirring are much finer and more uniform than those without electromagnetic stirring. High qualitative layers which are free of porosity and cracks are obtained from the laser cladding with electromagnetic stirring. The influences of different electromagnetic stirring strengths on the hardness of the laser cladding layers are also investigated. The results show that the hardness increases correspondly with the increase of the electromagnetic stirring strength.