Nautical silt specific weight is the key for both nautical resources and nautical depth.Taking Lianyungang port for example,the Lianyungang port sediment silt-site sampling and analysis are carried out.The mud rheology test,resistance test ship models and laminar-turbulent flow pattern changing theory,and nautical specific weight,which is the most important parameter for nautical resources,are analyzed .The results of Lianyungang port nautical specific weight are obtained and recommended values are proposed.