The main contents of this paper are the PQM system construction case and distribution system harmonic voltage analysis. The PQM system has constructed by KEPCO in order to investigate power quality of distribution power system for new power quality standard of KEPCO. In result, we have confirmed that voltage harmonic measurement value of the high voltage contract customer 8 households is suitable the KEPCO harmonic standard tentative plan. And the voltage harmonic value of distribution line end side is not always more high than source side by harmonic current offset effect. In the future, acquired data by season, region, load from the PQMS will be used on the resonable harmonic standard enactment in KEPCO.