This study was carried out to investigate the effects of herbicide treatment on the forage yield, nutrient productivity, weed control and persistency in the Rumex crispus dominated pasture in Suwon and in Youngam kom June, 1993 to October, 1995, respectively. It was arranged as a randomized block design with five treatments : 1. reseeding at middle August, 2. dicamba 2liter /ha+reseeding at early July, 3. dicamba 24liter ha+reseeding at middle August, 4.dicamba 2lliter /ha+reseeding at early July +dicamba 14 /ha and 5.dicamba 24liter /ha +reseeding at middle August +dicamba 1liter/ha. In the Rumex crispus dominated pasture, the treatments of dicamba 2liter ha+reseeding(early July or middle August)+dicarnba 1liter/ha were controlled 77-92% of the weed, and increased 105- 141% of forage yield and were higher 88-141% of energy (TDN and NEL) productivity compared with reseeding at middle August (control), respectively. The results indicated that herbicide treatment was effective for the control of Rumex crisps and renovation of grassland, and higher forage yield could be obtained by twice applications of dicamba.