Abstract: To acquire the marine radioactivity level around Hainan Changjiang NPP, two marine radioactivity surveys were conducted in 2009 and 2017. The medium, scope, frequency, site and item of two surveys were set according to officially issued standards or specifications. The methods of sampling, pretreatment and radiochemical analysis were also referred to the update standards related. The comparison result of two surveys show that the radioactivity levels in most of seawater, sediment and marine organism samples are not significantly different. It can be concluded that the operation of Hainan Changjiang NPP Unit 1 and 2 did not have an obvious influence on marine radioactivity level around the plant. It is suggested that 90Sr monitoring should be concerned in the future survey.