Vision-based BEV (Bird-Eye-View) 3D object detection has recently become popular in autonomous driving. However, objects with a high similarity to the background from a camera perspective cannot be detected well by existing methods. In this paper, we propose 2D Region-oriented Attention for a BEV-based 3D Object Detection Network (ROA-BEV), which can make the backbone focus more on feature learning in areas where objects may exist. Moreover, our method increases the information content of ROA through a multi-scale structure. In addition, every block of ROA utilizes a large kernel to ensure that the receptive field is large enough to catch large objects' information. Experiments on nuScenes show that ROA-BEV improves the performance based on BEVDet and BEVDepth. The code will be released soon.