The concepts and detailed design of channel width of Design Code of General Layout for Sea Ports（China）,Harbor Approach Channels Design Guidelines（PIANC,2014）,Spanish Recommendation for Maritime Works of Spain(Spain),New design standards for the ports and harbor (Japan)are introduced.Along with the comparisons of channel width of the one-way and two-way channel of typical container ship and VLCC by different cross flow,wind and ship speed,some useful conclusions are drawn.