Abstract: The paper briefly introduces the latest research results concerning the changes of the modern geo-environment along the muddy coast, including the global climate and sea level fluctuations in the geological history, projections of the sea level rise in the 21st century, extremely high water levels and New Orleans and the Netherlands cases. Based on an innovative extension of previous studies and the latest data obtained by the authors′ group, this paper presents the main factors influencing the geo-environmental changes on the west coast of the Bohai Bay, including existing altitudes, vertical sedimentation rates, land subsidence, sea level rise and sudden events such as extreme accumulated water increase. Furthermore, the authors present the idea of studying the muddy coast by considering the interaction of various factors and a suggestion of maintaining vigilance against the possible paludification trend along the muddy coast.