THIS RESEARCH WAS CONDUCTED AT FIELD CONDITIONS IN KHOOZESTAN, IN 2007 TO EVALUATE THE EFFICACY OF PENOXSULAN SC 240 AS A NEW HERBICIDE. PENOXSULAM AT 24, 30, 36 AND 42 G/ HA WAS COMPARED WITH TANK MIXED APPLICATION OF BUTACHLOR PLUS CINOSULFURON AT 900+20 G /HA, BUTACHLOR PLUS BENSULFURON AT 100+45 G /HA AND A MIXTURE OF ANYLOFUS AND ETHOXYSULFURON (SUNRISE) AT 945 G /HA FOR CONTROLLING ECHINOCHLOA CLONA, CYPERUS DIFFORMIS AND RICE BROADLEAF WEEDS. FOR E. CLONA CONTROL, PENOXSULAM AT 42 G HA-1 SHOWED THE HIGHEST EFFICIENT, HOWEVER, THIS TREATMENT HAD NO SIGNIFICANT DIFFERENCE WITH BUTACHLOR PLUS CINOSULFURON OR BENSULFURON.THE EFFECT OF PENOXSULAM AT 42 G/ HA ON C. ROTUNDUS WAS SAME AS TWICE HAND WEEDING AND BETTER THAN THE OTHER HERBICIDES. FOR CONTROLLING BROADLEAF WEEDS INCLUDING CLEOME VISCOSE, PORTULACA OLERACEA, PHYSALIS SP., PENOXSULAM AT 36 AND 42 G/ HA WAS SIMILAR OR BETTER THAN THE OTHER HERBICIDES.