This standard specifies the determination method of tin dioxide in tin dioxide, which is suitable for samples with tin dioxide content greater than 95%. The potassium iodate Titrimetric method is used for determination. First, the sample is melted with zinc powder and sodiumhydrate, and then leached with muriatic acid. The tin is reduced to the divalent state by iron powder and metal aluminum, and then using starch as an indicator, it is titrated with potassium iodate standard solution until the solution is light blue as the end point. This method can accurately determine the tin dioxide content in tin dioxide, providing effective technical support for quality control in related industries.