Abstract: The controlled release performance of an antifouling agent (4, 5-dichloro-2-n-octyl-4-isothiazolin-3-one) in copper metallized tubules is investigated in this paper. Electron microscope observation indicates that the antifouling agent can be entrapped in the metallized copper tubules effectively. The Uv-visible spectrophotometric detection manifests that the maximum entrapped quantity reaches 74% by the total weight of the sample and release rates vary with different encapsulation procedures. The maximum release rate is 0.35 mg/l/d, and the minimum release rate is only 0.1 mg/l/d suggesting that the copper metallized tubules are effective on controlling the release of antifouling agent.