The GB/T 15506-1995 standard specifies a method for the determination of filterable barium content in industrial wastewater using Atomic absirption spectropho-tometry, AAS, which is suitable for wastewater analysis in chemical and machinery manufacturing industries. The method detection range is 1.7 to 500 mg/L, and can be analyzed by diluting when the sample concentration exceeds the upper limit of determination. Coexisting elements such as sodium, mg, iron, etc. have no significant effect on the determination at a certain concentration. This standard provides a technical basis for the accurate determination of barium content in industrial wastewater and is suitable for the field of environment monitoring and water quality management.