With advance of urbanization and industrialization, modern agricultural development in China’s economic developed areas (CEDAs) is greatly restricted by traditional concept. To speed up the development of modern agriculture in CEDAs, this paper takes Suzhou City as an example from theories supporting modern agricultural development. It demonstrates agriculture in CEDAs plays an important role in adjusting supply of agricultural and sideline products, reserving rural labor employment, protecting ecological environment, increasing farmers’ income, and passing on agricultural culture. It contends that CEDAs should take reserving basic farmland as prerequisite; take adequate supply of primary agricultural products, protection of living environment, maintenance of agricultural landscape, and inheritance of farming culture as objectives; establish perfect modern agricultural system through firmly setting up modern agricultural value concept; increase local public finance input; increase agricultural functional value from technical and management levels, to realize increase of farmers’ income, promote sustainable development of agriculture, promote integrated urban and rural development, as well as harmonious development of human and nature.