The purpose and the value of standard reference materials (S.R.M.) are defined, and their increasing world importance is emphasized. The desirable features of an S.R.M. are outlined and the procedures necessary to meet, as far as possible, the necessary requirements in S.R.M. production are discussed. The method and organization of certification for homogeneity and composition are detailed, as well as the statistical proceduces to evaluate the certification analysis. The present Status and future plans for the production of S.R.M.'s by the Canadian Standard Reference Materials Project, Mines, Branch, Department of Energy, Mines and Resources, are outlined.