Abstract: 【Objective】In order to investigate patterns and distribution of races of Soybean cyst nematode (SCN Heterodera glycines Ichinohe) 【Method】A total of 38 sites in Huang-Huai valleys were sampled and identified for the distribution of soybean cyst nematode races during 2001- 2003. A map of race distribution was constructed according to the data from this experiment and literature cited. 【Results】Three areas mainly infested with Race 1 were identified, i.e. the area south-east to Jinan in Shangdong Province, the area of northern Henan Province and its border region to south of Hebei Province, and the area of Luohe, Zhoukou of Henan Province and Fuyang of Anhui Province. Race 4 was predominant in Shanxi Province, Beijing and the adjacent area of Henan, Shandong and Anhui Provinces, and the delta of Huanghe River in Shandong Province. Race 2 was mainly in Liaocheng, Dezhou of Shangdong province and Shijiazhuang of Hebei province, and Jiaozuo and Huojia of Henan Province. Race 7 distributed in the west part of Jiaodong Peninsula of Shandong Province and Kaifeng, Huaxian, Wenxian of Henan Province. Race 5 was found and scattered in Hebei and Henan Province. Race 9 was found in Shangqiu of Henan Province, which was reported the first time in China. 【Conclusion】From the above, Race 1 and Race 4 were the two predominant races in Huang-Huai valleys, which should be focused on for developing resistant cultivars. There might exist other races in an area with some predominant races. The race change in the past decade was not obvious, therefore, the results are meaningful to the present breeding for resistance to SCN in Huang-Huai valleys.

Key words: Soybean [Glycine max (L.) Merr., Huang-Huai valleys, Cyst nematode (Heterodera glycines Ichinohe), race