Abstract: Some problems existed with the 70 t UHP EAF as imported by Pangang Group Chengdu I&S Co. Ltd.during the trail operation period,including rather long melting cycle,high electrode consumption,water leakage as caused by frequent damage of the RCB lance and the water cooled panels by burning,low campaign and high gas contents in the liquid steel,etc.Owing to relevant investigations,causes for the said problems are identified,based on which corrective actions like optimizing the RCB oxygen-feeding schedule and the melting power-supply schedule have been taken,resulting in satisfactory effectiveness.