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Most of the water supply comes from Yellow River as the foundation in Jinan city of Shandong province.Due to the fast development of industry and agriculture around drainage area of Yellow River and large sewage,the water quality of Yellow River comes to deterioration.The most important contaminations are organism,nitrogen and phosphorus.The status of Yellow River as the drinking water quality is not optimistic.The present techniques of water supply factory in Jinan cant removal polluted substances such as nitrogen and phosphorous.So we need pretreatment to the raw water.Because constructed wetland is a kind of sewage treatment method as a lower cost,lower energy,lower technical-demanding,so we adopted this method to treat.Nowadays,the research on constructed wetland system always attaches importance on the effects on the biological role during the purifying process.And the non-biological role such as the soil that the plants and microorganism live by are neglected.In order to explore the influence of wetland soil on purifying the micro-polluted water,a soil-bacteria system is built in Yuqing Lake in Jinan to make simulated experiment research.The system is 16m×6m×0.8m deep,the average depth of water is 0.2m,base slope is 1‰,The media in the bed is local soil.In June 2006,the system began to run.with the load 2.7m/d.The raw water comes from Yellow River and the water quality index of raw water in experimental period is:the average of COD、TN and TP is separately as 32.59 mg/L、3.72 mg/L、0.04 mg/L.After six month research,Experimental data indicated:constructed wetland system has better treatment effect towards micro-polluted raw water without considering the plants.The average removal rate of TN and TP can reach 45%~50%.Removal rate of COD can reach 35%~40%,These figures can fully show that the soil plays an important role in treating nutriment and microorganism.Along the direction of inflow whole system,and the effects are different in different areas.The elimination of COD and TN mainly occurred in the former of system,with removal rates of 25% and 30% in COD and TN concentration respectively.This efficiency was much greater than the latter of system.During the function of the system,phosphor accumulates and it moves from the beginning section to the following sections.At the end of the experiment,phosphor saturates in the beginning section,which the direct reason that leads to the decrease of the removal rate.Because load is low and the removal function of system cant be fully used,so the future experiment can improve load in suitable time and fully used the removal effect ofsystem.