Abstract: MAP70s family members were screened and identified using the bioinformatics method based on the genomic database of B. napus, and bioinformatics analysis was performed on the sequence characteristics of the identified BnaMAP70s gene family members. Gene expression levels of BnaMAP70s gene family members were analyzed with qRT-PCR in seedlings of sensitive to waterlogging and strong waterlogging tolerance varieties. The results showed that 19 members of the BnaMAP70 gene family were identified, distributed on 11 chromosomes and they could be divided into five subfamilies. The upstream elements involved in anaerobic stress and phytohormones of the BnaMAP70s promoter indicated that they might involve plant growth, development, and regulation of waterlogging stress. And the transcription levels of genes are species-specific, plant site-specific and time-specific. The qRT-PCR analysis results showed that BnaMAP70-1 and BnaMAP70-4 were differentially expressed under waterlogging stress, indicating that these two genes were regulated by waterlogging stress.