Abstract: In oder to address the problem that narrow face of mould copper plate of thin slab continuous casting process present server wear and low service life,the effect of cooling structure of narrow face copper plate on heat transfer had been analyzed. A new copper plate used for improving cooling ability of mould narrow face was designed.The copper plate was cooled using five round tube shaped inner gullets whose inner diameter was 11 mm.When the amount of water was 230 L/min,the velocity of water could be increased from 6.23 m/s to 8.07 m/s,the convective heat transfer coefficient of water could be increased from 22 000 W/（m²·℃） to 29 000 W/（m²·℃）,and the hot side temperature of narrow face copper plate could be reduced about 25 ℃.Lots of industrial experiments had been made using this copper plate.The results showed that the maximum wear amount at the bottom of copper plate had been reduced from 4.5 mm to 1.3 mm,which made the service life of the narrow face copper plate equal to that of wide-face galvanized copper plate.In a general way,this narrow-face copper plate cooled by five round tube shaped inner gullets had many advantages including low additional taper,high heat flux,low hot face temperature and high wear resistance.