Taking dredging without siltation as the theoretical basis and current afflux as the key motive force, this paper presents the natural dredging method, which bears the effect of less siltation or no siltation following channel deepening. This method is applied to Lingdingyang channel of Guangzhou and achieves a satisfactory effect. Furthermore, the guiding opinion is put forward for the channel deepening engineering of Yangkou port in Jiangsu province and Jiaxing port in Zhejiang province.