In order to study of new brand of Cloridazon(Pyramin, WP 65%) efficacy on broad leaf weeds of Sugarbeet, an experiment was conducted in two locations(Golestan province(Gonbad station) and Khozestan province( Dezful station), 2018. Experiments were arranged as randomized complete block design with 4 replications. Treatments were: application of Pyramin at 3, 4 & 5 kg/ha, as pre-emerge and at 4 sugar beet leaf stages, application of phenmedipham+desmedipham+ ethofumesate (Betanal Progress OF at 3 lit/ha at 2-4 sugar beet leaf stages), and weed free as check. Weeds population(density and dry weight) were evaluated at 30 days after herbicide application and root yield of sugarbeet in the end of sugar beet growth. Results indicated that pre emergence application of Chloridazon(at 3 , kg/ha) was the best treatment( with more than 85% weed population control) in two locations. This treatment had no significant difference with Phenmedipham+desmedipham +ethofumesate. In khozestan, and if there is Malva neglecta as mostly weed, application of increased dose of Chloridazon (4 kg/ha ) will have better result. Anyway, application of chloridazon at more than 4 kg/ha will have negative effects on sugarbeet seed germination and not recommended.