Among the several factors responsible for the low productivity of rice, severe weed infestation offers the major obstacle to achieve higher yield. Weeds are one of the most important robbers of plant nutrients, moisture, solar energy and also the harbor of insect, pests and disease causing organisms, cause adverse allelopathic effects and increase cost of production. Thus, weeds are considered as a major pest and serious constrains of rice causes almost 35% yield losses. For combating weed menace, manual weeding is usually practiced, but it is labour intensive, tedious and does not ensure weed removal at critical stage of crop-weed competition. For the last many years, a number of pre-emergence herbicides like Butachlor, Thiobencarb and Anilofos are being applied for effective control of weeds mainly grassy weeds. These herbicides are of high doses and their continuous application insists the problems of environmental pollution, resistance in weeds and shift of weed flora.Considering these views application of Imazosulfuron, Ethoxysulfuron and Oxadiargyl can be effective for controlling all weeds and their dose is also quite low. These herbicides have minimum phytotoxicity too.