The pressures of population growth and socio-economic development activities has a great impact on the environment and coastal ecologies in Quang Ninh province. The pollutant sources from the production and domestic activities have caused the changes in some elements and coastal water quality in the study area. The analysis results of water samples along coastal zone of Quang Ninh from 2011 to 2013 shown that coastal water in Quang Ninh has been polluted by nutrition, organic matter, oil and heavy metals. Concentration of NH4+ at the monitoring sites exceed National technical regulation on coastal water quality (QCVN 10: 2008/BTNMT) for aquaculture and fisheries conservation from 1.4 to 2.9 times. In the Bai Chay tourist wharf, water has been contaminated by waste oil from boats, where content of oil was recorded as 0.312 mg/l, exceed 1.56 times the permitted regulation.