Abstract: The benefit of port investment is studied by introducing the economic early warning system. First, a benefit early warning index system is constructed; the model of early warning system for the port investment effect is built based on RBF neural network. Then this model is tested through historic figures of investment and benefits from year 1996 to 2005 on Chinese costal harbors. By testing model error throughdifferent spread coefficients, it turns out that when the spreadcoefficient value is defined as 0.6, the model error is 95.07%, under which the model can best predict the investment benefits of the harbors. At the end, the warning intelligence indicators are divided into three different early warning zones based on the historical data of port investment benefit.