In the evaluation of external quality control survey, the mean value of peer group has been using as the target value generally. However, there are some arguments about whether the mean value shows the true value of survey sample. In 1992 National Federation of Industrial Health Organization(NFIHO) established the committee for reference target value and studied the determining of reference target value. In 1993 NFIHO started the evaluation by the reference target value determined by the committee. In 1996 committee for external quality control survey of Japan Medical Association(JMA) started the evaluation by adjusted mean value of peer group. In 1999 JMA established the sub-committee for target value and published the study report in 2000. By using the result from the above two associations, I have studied the possibility of the evaluation by target value. I concluded as follows. 1)The good agreement was seen between the target values and the mean value of peer group. 2)The poor agreements were seen in some anaytes. 3)By increasing the number of laboratory in which the traceability is being confirmed, the better agreement will come to be seen between the target value and the mean. 4)To determine the target value, we need the long-term maintenance of laboratory performance and the consumption of large energy. 5)As for the analyte, which is possible to calibrate by reference measurement procedure and reference material, the mean value after the traceability was confirmed can be used as the target value.

*Health Care Technology Foundation, Shinjuku-ku, Tokyo 162-0804