IN ORDER TO INVESTIGATE THE MECHANISMS OF RESISTANCE TO DICLOFOP METHYL IN TWO RESISTANT PHALARIS MINOR POPULATIONS, COLLECTED FROM WHEAT FIELDS OF FARS PROVINCE DURING 2006, THREE EXPERIMENTS WERE CONDUCTED TO STUDY RETENTION, ABSORPTION AND TRANSLOCATION OF DICLOFOP METHYL IN THE RESISTANT (SR3 AND FR8) AND SUSCEPTIBLE (ES) POPULATIONS. THE AMOUNT OF HERBICIDE RETENTION ON ES WAS 16.68 ML PER G LEAF DRY WEIGHT, AND DIDN’T DIFFER WITH SR3 AND FR8. ALTHOUGH HERBICIDE ABSORPTION INCREASED AFTER THE TREATMENT, THE AMOUNT OF THE ABSORBED HERBICIDE WAS SIMILAR IN ALL POPULATIONS. ALMOST ALL OF THE ABSORBED HERBICIDE REMAINED IN THE TREATED LEAF AND ONLY A LITTLE BIT OF DICLOFOP METHYL WAS TRANSLOCATED TO OTHER PARTS OF THE TREATED PLANTS. PREVIOUS STUDIES HAD REVEALED THAT THE RESISTANCE IN SR3 PLANTS IS DUE TO PRESENCE OF INSENSITIVE ACCASE ENZYME, BUT FR8 PLANTS DIDN’T HAVE ALTERED ENZYME. THE RESULTS OF THIS STUDY SHOWED THAT THERE WAS NOT DIFFERENCE IN RETENTION, ABSORPTION AND TRANSLOCATION OF DICLOFOP METHYL BETWEEN FR8 AND SUSCEPTIBLE ONE; OTHER MECHANISMS INCLUDING ENHANCED METABOLISM, MAY BE INVOLVED IN FR8 PLANTS.