Withtherapidprogressingofscienceandtechnology ,Impactonthemeasurement ofpricemovementcausedbythechangeofproductqualityismoreandmoreobvious, andhasbecomeachallengetocurrentpriceindexcompilation .SNAhasmadesomepre liminarydiscussiontothisissuebutnotintodetails.Inthisarticle ,authorspointoutthe internalrelationsbetweenproductqualityandpriceindex ,discussthetheoreticaldefini tionofqualityindex ,andstudythecompilationofindividualqualityindexandensemble qualityindex .