Abstract
Methods for the determination of serum total cholesterol have been changing over a long period of time. The purpose of this paper is to verify whether the accuracy of determination changed during the period or not. I investigated the reports of external quality assessment about the change of method and the scientific reports about the accuracy of determination. The accuracy of determination during 1971-1991 was not clear because no report about the accuracy compared with the reference measurement procedure was found. However I found that the accuracy of determination after 1992 have not changed because there are the reference values obtained by use of the reference materials. As a result, I concluded that the change of accuracy was small over the past thirty years.
