Abstract: In order to detect the resistance level of Echinochloa crus-galli（E. crus-galli） from rice fields to penoxsulam in Anhui province and its distribution，whole-plant bioassay experiments were conducted to evaluate the resistance level of 40 populations of E. crusgalli from rice fields in different areas of Anhui province. Additionally，the resistant biotype with the highest resistance level was tested for sensitivity to 15 herbicides. The results showed that E. crus-galli in Anhui rice fields had varying degrees of resistance to penoxsulam. Among the tested samples，20 resistant populations accounted for 50% of the total number，including 13 medium and high-resistant populations accounted for 31. 5% of the total number. The resistance levels of E. crus-galli cwere much higher in the plain area along the Yangtze River and the Jianghuai hilly region，followed by a mountainous area of southern Anhui. In contrast，the resistance levels in plain regions in Huaibei Plain and Dabie Mountains were much lower. The resistant population R was resistant to metazosulfuron， bispyribac-sodium，quinclorac，cyhalofop-butyl，tripyrasulfone，sensitivity to pyraclonil， oxadiazon，thiobencarb，anilofos，and metamifop was lower. At the same time，it was sensitive to pretilachlor，butachlor，pendimethalin，butralin，and propanil.

Key words: Echinochloa crus-galli, penoxsulam, resistance level, resistance distribution, sensitivity