Abstract: The microstructure and properties of J55 steel were analyzed by chemical analysis,metallographic examination,etc.,and these parametens were discussed for continuous casting processing. The results showed that,the pearlite increased the mechanical properties of J55 steel,in which the content of pearlite increasing with that of carbon. While,the inclusions had a certain effects on strength and impact with size and shape. Furthermone,there were little effects on properties in the case of some overheat or orertime,but minimizing and eliminating banded microstructure on some extent.