Abstract: In order to get the deformation data of ship hull constructing in berth,FBG-based system was designed to monitor the structural creep and stress relaxation.The monitoring system was installed in an actual hull and te st conducted to analyze the factors which likely affect the hull structural deformation.Through measuring the structural deformations of hull in berth due to the combination effects of structure creep and stress relaxa tion,the major factor that is stress relaxation was verified.Data analysis also show that it is feasible and practicable to monitor the hull deformation for the long-term monitoring using FBG sensors,and validate the e xistence of the effects of structural creep and stress relaxation in the hull structure in the construction stage.In addition,the release rate of internal stress in ship hull structure was estimated based on the shell theory.