It is of great importance of cast-mould permeability to get sound EPC casting. The effect of factors on the permeability of dry sand and coating were discussed. The dry sand preferred round sands ranging from 25 meshes to 45 meshes AFS. Proper refractory materials and binders should be selected for coating and the coating density should be controlled. There has a preference for one coating layer. There isn’ t a common standard for test method of EPC coating up to present