Within agricultural ecosystems the interaction between crop and surroundings is quite complicated. In order to know the feedbacks of crop to surroundings in agricultural ecosystem, a research on crop productivity model is becoming important. This paper discussed the backgrounds of the emergency of crop productivity model, thinking that the crop productivity model was a means which could be used to simulate growth process by mathematical ways and computer technology, and analyzed the physiology of crop growth and the correlation between crop and surroundings. At the same time, it discussed four phases of crop productivity model developing, including infancy, youth, adolescent and maturity. Secondly, the paper summarized the crop productivity model's function of agricultural eco-environment protection from three aspects, including scientific research, management of crop, and analysis of agricultural decision, and discussed the disadvantages of crop productivity model. The disadvantages embodied in three facets: 1) though the simple crop productivity model could be used easily in practice, its regional adaptiability was too weak; 2) complicated crop productivity model had too much parameters to obtain, which made it difficult to use in practice; 3) the inconsistency of basic data format in different research areas also made the model's regional adaptability too weak. It's indicated in this paper that the establishment of universal and uniform basic data format is favorable to the extension and application of crop productivity model in other regions. Geographic information system (GIS) was emerged in 1960, which has powerful functions of obtaining, depositing, managing and analyzing spatial data, and is useful to solve the problem of weakly regional adaptability. Meanwhile, friendly interface is favorable to the extension in common users. Finally, the paper discussed the combination of crop productivity model and geographic information system, summarized some researches on friendly interface of crop productivity model, and pointed out that the establishment of universal crop productivity model interface is the focus of the future.