Abstract: Soil animal in Dehui agricultural experiment and demonstration bases of Northeast Institute of Geography and Agricultural Ecology were investigated with 5different straw mulch amount treatment in July and September, 2008. Soil animal were hand-sorted and identified to maize stubble mulch amount. We choose the hand-sorting method to capture the large soil animal, and the Modified Tullgren to capture small soil animal. We have analyzed and identified under a microscope, soil animal. A total of 5336 soil animal individuals was captured and fell into 44 families. Onychiuridae, Hypogastruridae, Chironomidae larvae were the dominant groups that account for 59.51% of the total captured. The result showed that: the amount of maize straw mulch increased soil animal abundance and diversity. Different amount of maize straw mulch on soil animal community structure had a significant impact. The amount of maize straw mulch a direct impact on amount of soil animal diversity.