The GB/T 11740-1989 standard specifies the determination of cadmium concentration in the atmosphere of residential areas by Atomic absirption spectropho-tometry, AAS, which is suitable for the determination of cadmium in total suspended particulate (TSP) and respirable particulate matter (PM). The method has high Sensitivity and low detection limit, and is suitable for air pollution monitoring. The cadmium in the sample is leached by dilute nitric acid heating and quantified. The standard details the reagents, equipment and operation procedures required for the experiment, providing reliable technical support for the assessment of cadmium content in the atmosphere.