Abstract: By using Braun-Blanquet Cover Abundance Scale method, the species diversity of Brase-nia schreberi community in Dongshan Town (Suzhou City, Jiangsu Province) and Zhuantang Town (Hangzhou City, Zhejiang Province) was studied, and the results showed that in these two towns, B. schreberi community was of simple species composition and relatively low species diversity. The Shannon-Wiener diversity index, Simpson ecological dominance index, and community evenness in-dex all increased obviously when the habitat shifted from pond center to bank nearby. B. schreberi community was similar in the same type habitats of these two towns, and of much more similarity in pond center than at bank nearby. Compared with Zhuantang Town, Dongshan Town had a greater difference of B. schreberi community between the two habitats.

Key words: Bt(Bacillus thuringiensis)gene, Rice, Soil enzymes