Abstract: 【Aim】 Tundra is a polar natural landscape. The species composition and temporal dynamics of insects were investigated in the tundra zone inChangbaiMountains,Northeast Chinafor providing a basis for the protection of insects and the research of co-evolution of insects and plants in tundra. 【Methods】 During 2005-2007, insect individuals were collected in the west and north slopes within the tundra zone in Changbai Mountains by using the net, lamp and pitfall methods from June to September in each year. 【Results】 In total, 4 634 specimens belonging to 550 species of 105 families of 11 orders were collected in the tundra zone in Changbai Mountains during 2005-2007. The species numbers and individual numbers of Lepidoptera, Coleoptera, Hymenoptera and Diptera were dominant, and their peaks occurred in July. The correspondence analysis showed that Lepidoptera was more adaptable to July, Coleoptera was more adaptable to August and September, and Hymenoptera and Diptera were more adaptable to June, respectively. The species number (382), individual number (2 571) and diversity index (4.673) of insects were the highest in July in tundra, while the species number and the individual number were the lowest in September, with only 22 species and 265 individuals. The species number and the individual number of insects in tundra were significantly positively correlated (R=0.992). The similarity of insects was very low between different months, with the similarity coefficient lower than 0.20. 【Conclusion】 The diversity of insects is low in the tundra zone in Changbai Mountains. The occurrence peak of insects is in July, and the individual number and the species number are the least in September. The species richness of Lepidoptera is the highest in the tundra, and Lepidoptera shows relatively strong adaptability to July with better environmental conditions. The Coleoptera insects adapt to environmental changes better than other groups and play an important role in maintaining the ecological balance of the tundra zone.

Key words: Insect, species diversity, community, temporal dynamics, tundra zone;ChangbaiMountains