Abstract: Urban agriculture was an important part of modern agriculture, and studying the agricultural economic structure to explore the direction of development of modern agriculture could promoted the harmonious development of the city industrial and agriculture. This paper took Nanchang City as an example, using the grey systems theory of the grey relational analysis to explore correlation degree among the agricultural economic structure, and explored the influence factors of urban agriculture economic structure. The results showed that animal husbandry and fishery had specific rapid development advantages in the urban agriculture, namely the animal husbandry and fishery had a most grey correlation value of agricultural output; although planting had a small relevance to agricultural output, but it grew at an average annual rate was still higher than the whole agricultural development speed. From investment perspective, the production efficiency and consumption were important factors associated to agricultural output. It demonstrated that urban agriculture economic structure, which was different with national and regional agriculture, was serve the needs of the development of the city.