SHIP & OCEAN FOUNDATION studies on Pilot Model for CIM in shipbulding. One of the subjects in this project, we researched on modeling for Piping Arrangement in Shipbuilding. This paper proposed Piping Arrangement Model based on Object Oriented and Entity-Relationship method. Following this concept, we developed Prototype System by Smalltalk80, this is object oriented program language and enviroment. The Prototype System applied to midship part of oil tanker and obtained efficiency of proposed Piping Arrangement Model.