This experiment was carried out to find out the optimum variety of com hybrids and to find out alternative crops in the rice black-streaked dwarf virus(RBSDV) prevalent area. Productivity of 4 Korean improved and 6 introduced com hybrids and RBSDV infection rate were tested for 3 years in both Cheonan(middle part of Korea) and Gochang(southern part of Korea). Percentage of RBSDV diseased plants differed depending on the hybrid and region.