The Baoan marine office, Chenyuan tank farm and our company held a united large-scale oil spill maneuver in Chenyuan dock; it was aimed at testing the ability of emergency response when the oil tankers leak during the oil unloading. The exercise was divided into three parts: oil spill, emergency report and emergency response. At 15:30 in the afternoon, we simulated that the tanker “Oil No.1” located in berth 1 leaked during oil unloading. The person in charge of the tanker reported to Baoan marine office immediately. We received the instruction from the marine office at 15:35 and set up a emergency command center soon. At 15:40 we sent off ships and relative personnel to the accident site. At 16:00 our cockboats and oil containment booms reached the site and started the containment in the neighboring sea area to stop the diffusion of the oil. At16:20 the emergency response ship arrived, it further controlled the condition and the staff start cleaning the oil contamination with the help of suction felts. At 17:00, the oil spill was under control and the staff kept cleaning the rest contamination. The exercise ended successfully at 18:00. The ability of coordination and emergency response got improved through the exercise.