In Brassica as matter of seedling manner, they have the bilocular ovary and 20~28 seeds per silique after fertilization. Rarely some of B. juncea and yellow sarson (Brassica rapa ssp, tricolaris) have multilocular ovary. In this stdudy, the LP8 (YS-033, CGN06835) is shown tetralocular ovary as well as high seed yields. As microscope study for the different size of immature bud sections and we have known the floral meristem with already four locules in immature buds less size than 1mm of LP8. To identify of determining of tetralocular ovary formation, RNA-seq was carried out on the isolated RNA from less than 1mm and from 1mm of bud size respectively. By contrast tetralocular ovay and bilocular ovary, Chiifu is used. A total of 994 differentially expressed genes(DEGs) are detected in only LP8. Among the DEGs, we identify 18 DEGs in only immature buds of less size than 1mm. The expression patterns of 18 DEGs are validated by real time quantitative PCR and these genes are cloned and the sequence analyzed. At present, 12 candidated gene are analyzed by sequencing and there are detected by large fragment insertion as well as SNPs in sequence comparison to Chiifu. We will perform the genetic transformation of these DEG genes in Arabidopsis for relation between genes and tetralocular ovary. Our results will be helpful in understanding for mechanisms of tetraovular ovary in Brassica rapa.