Abstract: In 2001-2002, 591 diseased specimens of soybean leaves collected from Huang-Huai Valleys were purified, then from them fifty SMV isolates were acquired by using direct tissue blotting immunoassay (DTBIA). Based on their response to ten differential hosts screened by Wang et al., seven SMV strain groups, SC-3 ~ SC-9, were identified and a new strain group SC-10 was discovered. The analysis of the data in present study (2001-2002) combined with those from Wang and Yang (1998-2000) showed that in Huang-Huai Valleys (Henan, Shandong, north Anhui and north Jiangsu) nine strain groups among SC-1~SC-10, except SC-2, existed with the major ones being SC-3 and SC-7 accounting for 29.21% and 23.60%, respectively, and second ones being SC-4 and SC-8 accounting for 10.11% and 8.99%, respectively. In Henan there were seven strain groups with SC-3、SC-4 as major ones and SC-5、SC-7as second ones; in Shandong, four ones with SC-3 as major one and SC-8 as second one; in north Anhui, seven ones with SC-7 and SC-9 as major ones and SC-10 as second one; in north Jiangsu, eight ones with SC-3 and SC-7 as major ones and SC-8 as second one. As for the individual strain groups, SC-3 and SC-4 existed in all the four provinces, SC-5, SC-6 and SC-7 in Henan, north Anhui and north Jiangsu, SC-1 and SC-8 in Henan, Shandong and north Jiangsu, SC-9 only in north Anhui, SC-10 only in north Anhui and north Jiangsu, while SC-2 was not found in Huang-Huai Valleys.

Key words: Soybean, Soybean Mosaic Virus (SMV), Strain identification, Strain distribution