IN ORDER TO INVESTIGATE THE EFFECTS OF VOLUNTEER POTATO DENSITY AND HERBICIDE TREATMENTS ON GROWTH AND ROOT YIELD OF SUGAR BEET A FIELD STUDY WAS CONDUCTED IN FARSAN, 30 KM NEAR SHAHREKORD IN 2008. THE TYPE OF DESIGN WAS RANDOMIZED COMPLETE BLOCK WITH FACTORIAL ARRANGEMENT AND THREE REPLICATIONS. TREATMENTS CONSISTED OF 4 TYPES OF HERBICIDES (CONTROL, PYRAMIN, GOLTEX AND BETANAL) AND 4 VOLUNTEER POTATO DENSITY (0, 1.2 AND 4 PLANT M-2). THE RESULTS SHOWED THAT THERE WERE SIGNIFICANT DIFFERENCES BETWEEN HERBICIDES AND VOLUNTEER POTATO DENSITY ON SUGAR BEET TRAITS. THE HIGHEST DRY WEIGHT SHOOT OF SUGAR BEET PLANTS WAS OBTAINED FROM PYRAMIN HERBICIDE WITH 41.1 G AND THE LOWEST WITH 29 G WAS BELONG TO CONTROL TREATMENT. THE HIGHEST LAI AND ROOT WEIGHT OF SUGAR BEET WITH 4.7 AND 740.3 G RESPECTIVELY WERE BELONGED TO PYRAMIN AND 0 VOLUNTEER POTATO DENSITY AND THE LOWEST LAI AND ROOT WEIGHT OF SUGAR BEET WITH 2.5 AND 275 G RESPECTIVELY WERE BELONGED TO CONTROL AND 4 VOLUNTEER POTATO DENSITY TREATMENTS. THUS, APPLICATION OF HERBICIDES IN ORDER TO DECREASING OF VOLUNTEER POTATO DENSITY COULD AFFECT GROWTH AND INCREASE WEIGHT ROOT OF SUGAR BEET PLANTS.