China's gross demand for aquatic products includes the demand for raw and processed products of urban and rural residents, net export demand and the weight loss over the process above. Based on the data of the Statistical Yearbook, weight loss part of the value and its proportion of total demand (weight loss ratio) is isolated according to the features in the process of supply and demand of aquatic products. Long term prediction of the gross demand for aquatic products is obtained through building gray system predictive models or linear prediction models or combination models with the time series data of the demand for raw and processed products of urban and rural residents, net export demand and the weight loss. From the results above, China’s total demand for aquatic products will reach 66.1841 million tons at the end of “The Twelfth Fiveyear plan”, more than 90 million tons in 2030, but not more than 100 million tons, 2-3 times of the current level.