Abstract: To find out the output of oil sewage in the bilge compartment of marine fishing vessels of China, the bilge oil sewage of the marine fishing vessels in main fishing areas of China’s eastern coastal areas was sampled and investigated, and the estimation and analysis were carried out to know the annual total amount of the oil sewage discharged by China’s marine fishing vessels. The calculated data showed that the total annual displacement of China’s marine fishing vessels was about 136118 t, and the total annual oil discharge was about 5238 t. It is concluded that: the amount of oil pollution is not directly related to the ship age, however, the ship is in a better condition under the age of 5 years; the oil content of oil sewage is basically less than 5%, and the oil content of the lower water after a long static time is still higher than that of the discharge standard; and the oil sewage output from the marine fishing vessels is related to the daily management. Suggestions are put forward as: strengthening the publicity to improve fishermen’s awareness of environmental protection; strengthening supervision to reduce the emission of fishing vessels; encouraging fishing vessels to collect pollutants; strengthening cooperation and establishing coordinati on mechanism of various departments; strengthening research and development to promote technological innovation on oil sewage processing in the bilge compartment.