The raw material of potassium sucrose octa sulfate was examined for the preparation of the "Potassium Sucrose Octa Sulfate Reference Standard (Control 961)". Analytical data obtained were as follows: infrared spectrum, the same as that of the Potassium Sucrose Octa Sulfate Reference Standard (Control 901); high-performance liquid chromatography, one impurity was detected; water content, 8.1%; assay of sucrose octa sulfate, 99.6%. Based on the above results, the raw material was authorized to be the Potassium Sucrose Octa Sulfate Reference Standard of the National Institute of Health Sciences.