APETALA2/ethylene response factor (AP2/ERF) transcription factor (TF) superfamily plays an important regulatory role in signal transduction of the plant response to low temperatures. Significant progress has been made in understanding the cold resistance mechanism in B. napus, an important oilseed crop. However, no comprehensive studies have been conducted on the dynamics of accumulation of these TFs under low temperature. In this study, 132 AP2/ERF genes were identified using the transcriptome sequencing from the rapeseed leaves exposed to 0, 2, 6, 12, and 24 h of low (4 °C) temperature stress. They were classed into 4 subfamilies (AP2, DREB, ERF, and RAV) and 13 subgroups, among which DREB subfamily and ERF subfamily contained 114 genes, but no genes were assigned to soloist and DREB A3 subgroups. One-hundred eighteen genes were located on chromosome A1 to C9. GO functional analysis and promoter sequences analysis revealed that these genes were involved in many molecular pathways to enhance cold resistance in plants. Their expression patterns showed dynamic control under different stages of the stress, the RAV and DREB subfamilies were expressed at the early stage of cold stress, whereas the AP2 subfamily was expressed later. Subsequently, quantitative PCR analyses of 13 cold-induced AP2/ERF TFs confirmed the accuracy of above results. This study is the first to dynamic analysis the AP2/ERF TFs responsible for cold stress in rapeseed, the findings may serve as references for future functional research on the transcription in rapeseed.