Abstract: A F2 population derived from a cross between apetalous line‘ APT02 ’and normal petalled cultivar ‘ZS NO.4’ was used for molecular markers and mapping of the gene(s) controlling petal-loss trait in Brassica napus．20 pairs of AFLP primers and 170 pairs of SRAP primers were selected between two parents.Selecting further through bulked segregant analysis(BSA)approach, One SRAP marker e8m3_4 (600bp) and one AFLP marker E3247_15（150bp）were obtained to be linked to the gene(s) controlling petal-loss trait,with the genetic distance of 5cM and 13.5cM. A linkage map in Brassica napus was constructed. It was consisted of 213 AFLP and 56 SSR loci and a morphology marker in 17 main linkage groups, two triplet and four linkage pairs. Total length of the map covered 2487.1cM，Average interval between markers was 10.09 cM. By genetic mapping, the gene(s) controlling petal-loss trait (WHB)was mapped in LG4.