Abstract: Based on the eutrophication status and river channel characteristics of Liwa Creek, with the establishment of threedimentional plant communities and animal communities, the approxnatrual restoration engineering was carried out after traditional environmental engineering techniques. By comparing the changement of water quality, plant and animal communities in Liwa Creek before and after the engineering, the effects of this approxnatural restoration engineering were validated in this paper. The results show that after oneyear’s approxnatural restoration engineering measurement, TN and TP dropped respectively to 0.41 mg/L and 0.03 mg/L; contents of chlorophyll a dropped to 7.86 μg/L; Water quality was improved to a large degree, changing from the original class V to class Ⅱ standard. Besides, with the direct introduction of zoo benthos which filter feeding algae, Silver carp and bighead carp, biodiversity of animal communities is improved to a certain degree during the regulation of algae biomass. Practice proves that approxnatural restoration engineering is effective in the case of Liwa Creek based on low cost, which can finally be promoted during the approxnatural restoration practice of urban ecosystem.

Key words: urban river, ecosystem restoration, food chain rebuilding, approx nature restoration, urban river, ecosystem restoration, food chain rebuilding