The world vertical upward flow round critical heat flux experimental database is analyzed based on the slice method,similarity measure,heat balance and inlet temperature verification.Finally,a re- vised CHF data is obtained after abandoning 522 bad database points,326 outliers,1640 duplicated data,619 heat unbalance data and 10 inlet temperature violation data.The present work is the base for the development of new CHF models,new corrations and new CHF look up table.