Abstract:A high quality BAC library of the oilseed Brassica juncea variety Sichuan Yellow Seed was constructed to accelerate the study and utilization of the yellowseed rapeseed genome.The library contains 82 944 clones and is stored in 216×384 microtiter plates.The results of restriction enzyme digestion of plasmid showed that the average insert size of the library was about 140 kb and the emptyvector rate was about 2.5%.Based on the Brassica juncea genome size of 1 000 Mb,the library covers about 11.6× genomes.The results of Blast analysis of the BAC end sequences showed that the clones were evenly mapped onto the 18 chromosomes of the Brassica juncea genome.No chloroplast,mitochondria and bacterium genome DNA contamination was found.