Reclamation is adopted by many coastal countries to develop living space. Although reclamation changes natural coast pattern in local small scope, which most happen on beach area or shallow ocean area. Therefore, it has heavy destroy to local natural system, brings negative effect to coast area ecological environment stability, biodiversity and sustainable development. The paper takes constructing Lianyun new city as example. Biomass changes before construction and during construction at four monitoring spots are analyzed, negative effects to natural environment, marine product yield and marine animals' survival environment are deeply discussed. In order to develop marine ecology , several piece of advices are advanced in the paper to reasonably exploit coast resource and protect natural ecological environment.
