Identification, understanding, and prediction of many interdisciplinary biological and oceanographic processes remain as elusive goals of ocean science. However, new ocean technologies are being effectively used to increase the variety and numbers of sampled variables and thus to fill in the gaps of the time-space continuum of interdisciplinary ocean observations. The formulation, accuracy, and efficacy of data assimilation are highly dependent upon the quantity of interdisciplinary observational data. This review aims to describe the work carried out to-data on the data assimilation into marine ecosystem model and the techniques developed for the assimilation of data into marine ecosystem model. Compared with the meteorological forecasting, the data assimilation into marine ecosystem model is in its infancy. In addition, the developments and applications of data assimilation into marine ecosystem model in China was summarized and the related problems were presented.