In the coming decade, Laizhou Bay coastal areas will be the important areas of the intensive sea-use in Shandong Province. In order to reduce and minimize the possible adverse impacts imposed by marine engineerings on the marine ecosystems and to determine the appropriate scales and sites of the intensive sea-use projects, the eco-environmental quality from 2004 to 2012 is evaluated based on habitat quality and ecological response using the constructed index system and method of marine ecological impact assessment in the present study. The result showed that the eco-environmental quality of the region I and IV in the western and southern offshore areas of Laizhou Bay was poor. Habitat Quality Composite Index (HQI) evaluation suggested that these two regions were generally in mild to moderate pollution level, and the water quality and marine biological quality were more seriously polluted. It is clear that the inorganic nitrogen and oils greatly impacted on water quality, while the heavy metals and petroleum hydrocarbons greatly impacted on the biological quality, which were analyzed using the single-factor contribution rate of the water quality comprehensive index. The results of Ecological Response Composite Index (ERI) evaluation indicated that the ecology of the two regions were moderately or severely disturbed, and the density value of the phytoplankton and zooplankton greatly deviated from the standard value, while the biological density and the biomass of the macrobenthos less deviated from the standard value. However, the species composition has been significantly changed, and the number of the fish eggs and prelarva has drastically declined. The main reason for poor eco-environmental quality in Ⅰ and Ⅳ regions is the Yellow River and the Xiaoqing River, which are the primary pollution source of Laizhou Bay. The estuaries of these two rivers are located in Region Ⅰ, and much freshwater input resulted in the settlement and retention of various pollutants carried in runoff in western coast of Laizhou Bay. Region IV, located in the south of Laizhou Bay, is the estuary of the Mi River, Yu River and Wei River, and is impacted by the southwest Xiaoqing River estuary by the a alongshore current. Additionally, the two regions were also affected by the coastal agricultural non-point source and the pollutant emissions of the aquaculture. Therefore, it is necessary to strictly control the scale of the intensive sea-use projects and the new pollutant emissions in Region Ⅰ and Ⅳ in Laizhou Bay, and to pay close attention to their impact on the marine environment. The eco-environmental quality of Region Ⅱ and Ⅲ, located in the central and east of Laizhou Bay respectively, was close to the normal level. The habitat quality was at the light pollution level in general, the water was polluted to some extent, and the ecology was moderately disturbed. Overall, the eco-environmental comprehensive index value (E) of Laizhou Bay from 2011 to 2012, was obviously higher than those of other years, and the ecological environment was likely to obviously improve.