Applying underwater antifouling paints is a solution to prevent biofouling problems of ship vessels, but these paints often contains toxic heavy metals or herbicides. Therefore, developing new environmentally friendly antifouling paints is an important issue in marine technology. In this study, micro/nanocapsules encapsulated with antifouling agents was prepared by emulsifier-free emulsion polymerization method and introduced into antifouling topcoats, which allowing antifouling agents to be released persistently and achieving the purpose of environmental protection and long-term effect.