The layout of hydrologic network in the Changjiang estuary, based on analysis monitoring requirements of seven hydrological factors including tidal level, discharge, wave, salinity, sediment, water quality, wind speed and direction, was formulated with hydrological stations which controlled the critical regions or in the key nodes in this paper. The construction thought of hydrologic network is highlight the main factor, multifactor monitoring, integrated monitoring and retrench the network. The basic construction principles are emphasizing focal point, holding overall consideration, integrating the old and the new stations, substantiating and improving the network, considering every station and the network simultaneously, combining flow measurement in fixed satation and the moving gauging. 