This standard specifies the reagents, equipment, sampling and test methods for the determination of total tin in marine anti-fouling paint by Graphite furnace atomic absorption-tion spectrometry, GFAAS (GFAAS). It is suitable for the determination of tin content in marine anti-fouling paint, especially the identification of anti-fouling paint using organotin compounds as biocides. The standard details the acid dissolving treatment of the sample, the improvement method of the matrix, and the calculation and judgment of the determination results, which provides a scientific basis for accurately evaluating the tin content in anti-fouling paint.