Abstract: Based on the corrosion leaking of B30 copper nickel alloy heat exchange tubes of the condenser for ships,the observation of corrosion appearance and the analysis of ography and corrosion products on tubes were discussed. The results show that the component of B30 heat exchange tube satisfies the requirements of design,but the distribution of the metallographic structure of inside and outside surfaces are not uniform. The main cause of corrosion invalidation is the corrosion of inside surface,the micro aspect that the rich copper phase dropped as a result of the rich nickel phase corroded first,and the macro aspect that B30 heat exchange tube corroded with a hole on its surface as a result of the pitting corrosion deepened and expanded.