Abstract: In this work,objective and subjective video quality assessment methods are reviewed and the emphasis is put on the objective one.PSNR (peak signal noise ratio) and MSE (mean square error),the two commonly used assessment methods,are analyzed and their shortcomings are figured out.In addition, the objective video quality assessment is divided into the two broad categories,namely the human vision based one and the structure distortion based one,and simulation results are reported to show the performance of typical algorithms.Finally,we also list some predictions on the future trend and possible promising issues.