Awn, one of the domestication-related traits in rice might play an important role in seed dispersal. In a previous study, one major QTL, awn8 was detected on chromosome 8 using 120 RILs and 62 ILs derived from a cross between Hwayeongbyeo and O. rufipogon Griff. (Acc. W1944). We developed 140 BC1F3, 341 BC1F4 and 1533 BC1F5 plants from selfing of one plant selected from former generation. Each of selected plant was Hwayeongbeyo/W1944 heterozygous in the target region of chromosome 8. The Target marker(RM256) significantly linked to awn8 explained 60.3% of the total phenotypic variance in BC1F4 generations and the W1944 allele increased awn length. Using several substitution mapping, The awn8 QTL could be narrow down to the interval between RM23338-RM5485, with a distance of about 85.29kb. Total of ten genes were predicted in this region. At the same time, 34 BC3F5 lines were developed as the diverse NILs on chromosme 8. Using these NILs, One QTL for primary branch was detected in the target region and W1944 allele increased branch number. Characterization of the awn8 QTL would contribute the understanding of rice domestication and evolution and additional experiment would be need to be clarified whether awn8 and pb8 was due to linkage drag of independent genes or pleiotropic effect of the same gene.