The raw material of thiamine hydrochloride solution was examined for the preparation of the "Thiamine Hydrochloride Solution Reference Standard (Control 971)". Analytical data obtained were as follows: assay by HPLC, 100.8%; spectrophotometric assay, 99.8%. Based on the above results, the raw material was authorized to be the Thiamine Hydrochloride Solution Reference Standard of the National Institute of Health Sciences.