Quantitative study of non-point source pollution removal efficiency is of significance in effective management of ecological embankment construction. Therefore

this work put forward a new concept of pollution removal efficiency of ecological embankment and the simplified calculation model. Meanwhile

several empirical formulas of key variables in this model were deduced based on the rainfall simulation tests under different ground cover in Changshu City

including pollutant concentrations in runoff water

sediment concentrations in runoff water and pollutant mass concentrations of sediment in runoff water. As one case study for the ecological embankment with a gradient and subsurface treatment system used for Jinjingtang River in Changshu City

the results showed the comprehensive pollution removal efficiency could reach 75.4%

which was in good agreement with experimental data. As a kind of quantitative analysis method of environmental benefits of ecological embankment projects

the establishment of the model had obvious engineering significance.