The study of homogeneity and stability of samples is one of the most important links in the research and development of reference materials.According to the requirements of homogeneity and stability of the first-class certified reference materials,the homogeneity and stability of reference material candidates for the analysis of the precious metal composition of black shale were studied in this paper.The homogeneity test of 8 precious metal valuation elements (Au,Ag,Pt,Pd,Rh,Ir,Os,Ru) of the reference material candidates was carried out,the measured F values of all elements were lower than the F theoretical critical value by single factor analysis of variance,which indicated that the samples were homogeneous; the short-term stabilities of the samples under the extreme conditions of low temperature -20 ℃ and high temperature -60 ℃ and during transportation were investigated,and the results were consistent;in 21 months,the valuation elements and variable components of the samples were tested at 5 time points,the frequency of which is carried out dense at first and scattered after,and through one-way variance test,the measured F value is less than the theoretical value,the results indicating that the values of the characteristic parameters were stable during the investigation period.The homogeneity and stability of the prepared reference material for the analysis of the precious metal composition of black shale meet the research and development requirements for reference materials.Through the stability evaluation,the stability of this reference material is defined as 5 a.