Monochoria vaginalis is one of the dominant weeds in rice crop fields of Central Java and East Java Indonesia and it failed to be controlled by herbicides with the active ingredient bensulfuron-methyl. The research was carried out using split plotdesign with the dosage of bensulfuron-methyl as a main plot (0, 80, 160, 320, 640 and 1280 g a.i. ha-1 ) and Monochoria vaginalis from 5 areas as a subplot. The research was done from January until August 2019. Resistance ratio test of Monochoria vaginalis was performed using the whole plant pot test method. Results showed that Monochoria vaginalis originating from Kedaton, Tambakrejo, and Plumpang villages Indonesia was confirmed to have developed into weeds resistant to the methyl bensulfuron herbicide.
