According to the status quo of and requirements for the navigational channel protection,the paper analyzes the contents of channel regulation and main factors affecting the stability of navigation channel.The paper also discusses the basic requirements and foundation work for the delimitation of the protective area of a navigational channel.Taking the first phase of 12.5 m navigational channel project in the Lower Yangtze River for example,the paper provides practicable recommendations as to the process of the delimitation of navigational channel protection area.