Abstract: The major research progress in the application direction of agroecology in the first 3 years of the 21st century is summarized, including the utilization of agricultural biodiversity; the application of chemistry and ecology in agricultural production; the exploitation and utilization of traditional and new plant nutrition; the model construction of agroecosystem and field ecosystem; the ecological impact of water saving technique, covering technique and no-tillage technique; and profound research on alternative agriculture, such as ecoagriculture, organic agriculture. Future research focuses of agroecology are also proposed.