Abstract: According to the pollutant burden dixchargedinto Datong River from the factories, a simulation test in theeffect of Organic sewage irrigation on rice growth was conducted. The results are as follows:the:severe effect of sewage irrigation on rice growth and yield will appear when the organicmattet amount in the sewage water reaches to the critical level; and the rice growth and yield also is negatively affectedwith the irrigation of Datong River,which indicates that Da-tong River has been already severely polluted.

Key words: simulation test, sewage irrigation, rice growth