The thickness of reinforcement cover plays an important role to guarantee the bond between concrete and steel,and to improve the structure durability.This paper introduces the inspection at the entity structure of reinforced concrete in marine works,analyzes the bias of the inspection result with the current specifications,discusses the relationship between structure durability and the bias of reinforcement protection cover thickness,bearing capacity and the bias of cover thickness,so as to arise the attentions of construction parties,and further improve the control quality of the cover thickness in marine works.