Abstract. In this paper, we propose a new video watermarking algorithm based on the human visual system (HVS) properties to find effective locations in video sequences for robust and imperceptible watermarks. In particular, we define a new HVS-optimized global masking map for hiding watermark signals by combining the frequency masking, the spatial masking, and the motion masking effects of HVS. In this paper, we generate the watermark by the bit-wise exclusive-OR operation of a logo image and a random sequence, and we embed the watermark in the uncompressed video sequence. The amount of inserted watermarks is controlled by the peak-signal-to-noise ratio of the watermarked frame. Experimental results demonstrate that the proposed method is imperceptible and robust against various attacks with a good watermark capacity.