The calculation of deficiencies exists in the Design Code of General Layout for Sea Port concerning the channel width for the very large vessels required. This paper analyzes the effects of the leeway and the drift angle resulted from current to the width of ship’s tracks. A calculation method for the ship’s track width based on a series of simulation trials’ results using the linear regression method is presented , which had tested by a real project. It may serve as reference for the design and maintenance of the port and shipping engineering.