This study was carried out to map Bphl and bph2 gene in Mudgo and Sangju13 (Oryza sativa L.) respectively conferring resistance to brown plan-thopper (BPH) and to establish the marker-assisted selection (MAS) system. Bulked seedling (grown for 20 days) test was conducted with the 73 F4 lines derived from a cross between Nagdongbyeo and Mudgo for Bphl and with 53 BC3F5 lines derived from the Milyang95/Sangju13 cross for bph2. Bph1 was mapped between RG413 and RG901 on chromo-some 12 at a distance of 7.5 cM from RG413 and 8.4 cM from RG90l. A recessive gene bph2 was located near RZ76 on chromosome 12 at a distance of 14.4 cM. Bphl and bph2 were linked to each other with a distance of about 30 cM. An RFLP marker, RG413 linked to Bphl, was converted to an STS marker to facilitate the marker-assisted selection. BPH resistant genotypes could be selected with 92% accuracy in a population derived from a line of NM47-B-B.