Abstract: Based on the observation data in summer and winter, 2013, to analyze the seasonal variation characteristics of temperature, salinity, turbidity, Chlorophyll a, and Dissolved oxygen.The results show that the temperature isgreatlyaffectedbydifferentseasonswith obviousseasonaldiversity, and the summer temperature decreases from the inshore to the offshore, however, the temperature increased from the inshore to the offshore in winter, being significantly lower than in summer; The salinity is greater in winter than that in summer, and a low salinity tongue along the south flowing in the south of the estuary in both season, but the range is greater in summer than that in winter; The suspended sediment concentration and sediment transport scope are greater in winter than that in summer, and two maximum turbidityareas are located in the north and south of the estuary, and the bottom turbid is far greater than the surface, which indicates the small and medium-sized rivers also have the distributions of storage in summer and transport in winter as the large rivers; The Chlorophyll a and Dissolved oxygen is greater in winter than that in summer, indicating the negative correlation between Chlorophyll a, Dissolved oxygen and temperature.The hydrological environment factors exhibit obvious periodical with tidal changes trend.The temperature, Chlorophyll a and Dissolved oxygen increases during ebb tide, and decreases during the flood tide, showing bimodal structures with different peak value in one day.The maximum value of turbidity appears after the larger velocity has reached, which indicates most water column sediment is provided by seabed sediment re-suspended.