Capability verification is an effective way to judge,monitor and evaluate laboratory testing level.Shaanxi Institute for Product Quality Supervision and Inspection participated in the capability verification(No.CTC PT-2020-17)of free formaldehyde content determination in interior wall coatings organized by China Building Materials Inspection and Certification Group Limited Corporation.The absolute value of|Z|=0,indicating that the analysis results were reliable.Combined with the results of ability verification,the matters needing attention in the process of formaldehyde determination were analyzed and reasonable suggestions were put forward.