Abstract: Gross α and gross β in seawater, sediments and organism samples collected in 2012 and 2013 from the adjacent sea area of Yangjiang Nuclear Power Plant were measured by coprecipitation method. The results showed that in 2012 and 2013 gross α in seawater averaged 0.134 (0.083-0.205) Bq/L. Gross β in seawater averaged 0.043 (0.029-0.059) Bq/L. The gross α and gross β levels were lower compared with those from other sea areas. In 2012 and 2013 gross β in surface sediments was 814 (620-1 125) Bq/kg in average. The gross β level was at middle level compared with those from other sea areas. In 2013 gross β in marine organisms averaged 39.4 (16.1-74.7) Bq/kg. The averages of gross β in fishes, shrimps and shellfishes were 64.6, 36.8 and 16.7 Bq/kg, respectively.