In this paper, issues in design of an SoC based object-detection will be discussed, and an on-going hardware design base on YOLO algorithm and ARC Platform will be presented. With the optimization in both numbers of Processing Elements and Memory Bandwidth, A 176.3 GOPs CNN accelerator with 30 fps performance at 400MHz is presented. In addition to the Object- Detection engine, a ZCA image preprocessor and NMS postprocessing are also proposed to simplify the corresponding CNN model and enhance the real-time performance of Object- Detection. The emulation results and demonstration videos in the ARC platform will be presented. The post-layout simulation of current design verified the targeting real-time performance in a 28nm CMOS technology.