ABSTRACT: Analysis of the different gene expression profiles of natural and resynthesized Brassica polyploids with Illumina deep sequencing technology could help to improve our knowledge of polyploid genome evolution. We obtained approximately 6 million sequence tags per sample,and 6018254, 5930726, 6022170, 5950123, 5991210, 5798939, 5823113, 5772449,5858527 and 5657697 clean tags were obtained in libraries of B. rapa, B. oleracea, B. napus-F1, B. napus-F2, B. napus-F3, B. napus-F4, natural B. napus, B. nigra, B. juncea and B. carinata, respectively.16574, 15970, 22059, 18155, 16479, 18196, 17448, 13867, 19424 and 16645 genes of B. rapa genome were unambigously mapped by sequence tags of these ten DGE libraries, respectively. Differentially expressed genes during polyploidization were broadly discovered by comparing the tetraploids with their progenitors. mRNA obtained from young leaves of 28-days-old seedlings were compared during polyploidization.