The 12.5 m deep navigation channel of the Yangtze River from Nanjing to the Yangtze Estuary is a very important project to elevate the traffic capacity of the river and make the best of the Golden Waterway.It is important to study the influence of its building up on the economic development of Jiangsu province along the river.A model is developed on the basis of system dynamics for the influence of the Yangtze River deepwater navigation channel upon economy along the river.In accordance with the“6-in-1 theory of port,waterway,ships,cargos,information and finance”,the model consists of modules of economy along the river,ports,navigation channel & shorelines,financial investment and population.The model is improved by bringing in the unidirectional heat conduction and entropy increase of the Second Law of Thermodynamics.The result shows a better agreement with the real situation.It could be used to predict the relationship between the navigation channels of long inland rivers and economic development along them.