Based on the survey of the main marine fishing villages in Ningbo, this paper analyses the composition of marine fishing cost. The results are:(1) Not cosidering the labor costs,the fishing boats' profit is 75% in Fenghua. Otherwise,the loss rate is above 50%. The greater the power of the fishing boat is, the higher losses are; (2) Through the unit costs yield (including labor costs) and unit fuel costs yield, we found that two indicators of marine fishing boats are negative (loss); (3) Fishery taxes cost little, fishing boats financing way is mainly divided into wholly owned and joint ventures. Main conclusions are obtained through the results: (1) The ice, fuel costs and labor costs are the most important factors affecting marine fishing boats benefit; (2) The seasonal variation, taxes and allocation problems affected the cost benefit to some extent; (3) The problems of labor turnover and workers' education degree must be solved urgently in the future marine fishing.