Many studies on system reliability of marine structures have been done using framework models. There are, however, many structures which are difficult to idealize by a framework model. So a new system for plate structures using spatial membrane elements was developed to offer the expansion of the applicability of the structural system reliability by authors in the previous studies. In this paper, the features of the structural reliability of a large bulk carrier (150, 000 DWT) based on the collapse mode analysis are investigated by successively applying the newly developed system. From the analytical results for the spatial plate structures idealized for modeling the midship part and fore/aft L/4 parts of the ship hull structure under two loading conditions, main conclusions are summarized as follows : (1) New formulas of the compressive strength are derived for the longitudinal and transverse frame system panels under in-plane compressive and shearing stresses and lateral pressure, and the effects of the shearing stress and lateral pressure on collapse modes and the system reliabilities are investigated. (2) Effects of the shearing stress on the dominant collapse modes including damages of side shell elements and their occurrence probabilities in the fore/aft L/4 parts of the ship hull structure are more remarkable than in the midship part. (3) It is also pointed out that another results for deteriorated structures considering the notional corrosion damage referred to the class NK report are in comparatively good correspondence to the features of structural damages due to corrosion at fore/aft parts of aged bulk carriers.