Abstract: Mariculture is an important pillar industry of aquaculture in Hebei Province. The spatial-temporal variations in the seawater quality in mariculture area of Hebei Province were studied by the monitoring data from 2000 to 2010 and the seawater quality was evaluated by the fuzzy synthetic evaluation method and the single factor pollution index method in order to preserve the ecological environment of mariculture area and ensure the sustaining development of the mariculture. The results showed that the seawater quality in the mariculture area in Hebei Prvince was shown better in recent years. The seawater quality of mariculture area in Qinhuangdao and Tangshan met the requirements of aquaculture water, but the seawater quality in Huanghua was polluted seriously and did not meet the requirements of aquaculture water. The major pollutants in seawater in Hebei Province mariculture area were PO3-4-P and DIN, followed by Pb and Hg.