In Myanmar,Bandicota bengalensis is the main rodent pest and is ranked as the second most important constraint to production in lowland rice ecosystems.Previous studies in Myanmar reported weeds can provide a refuge area and alternative food source (seeds) for rodents during their breeding season.Further,weed growth and survival may increase in the open space created when rodents damage rice crops.However,little is known about the interaction of weeds and the population dynamics of rodent pests in rice-based cropping systems in South East Asia.In 2012-2013,a study was conducted in Bago Region,Myanmar to examine the relationship between weed and rodent interactions.A replicated study (n=4) compared 4 treatments (rodents and weeds; no rodents and weeds; rodents and no weeds; no rodents and no weeds) .Hand weeding was undertaken when necessary in best weed management plots (BM) .We examined rodent damage,rodent population dynamics,yield loss caused by rodents,the relative abundance of different weed species,and the biomass of weeds from BM and FP (farmer practices for weed management) .The abundance index of rodents in BM was lower than that in FM.Rodent damage in BM (7%) plots was significantly lower than in FM plots (17%) .The mean yield loss caused by rodents was 14%.Our study provides clear evidence of a positive relationship between weed biomass and rodent abundance.Weed control in and around rice fields combined with coordinated community trapping of rodents during the tillering stage of rice are recommended management options.