【Abstract】 Objective To grasp the community structure and quantity fluctuation of rat?shape mammals and provide the scientific basis for the evaluation and control of the mammals. Methods Rat?shape mammals were captured by night trapping method along the washland of the “Three?rivers” in Leshan city from September 2007 to August 2008. Results There were four species of rate?shape mammals. Among them, Anourosorex squamipes(49.55%) and Apodernus agrarius(45.34%) were the dominant species, Crocidura shantungensis(3.60%) was the common species, and Rattus norvegicus(0.90%) was the rare species. Seen from the quantity fluctuation of rat?shape mammals, there were two peaks in the whole year. One was in July and the other was October, but the peak value of the former was prominently higher than the latter. In winter and spring, the quantity basically maintained a lower level. And then, it began to go up quickly in June. By and large, the quantity fluctuation of the two dominant species also accorded with the rule.  Conclusion An.squamipes and Ap.agrarius were the main targets to prevent and control.