Yellow-top weed, Flaveria bidentis, is an important alien invasive plant recorded in 2001 in China and has been spreading rapidly since then. It is now widely distributed in Tianjin city and Henan province. The present paper reviews the achievements of studies in biology and ecology of yellow-top weed, including its classification, morphology, growth and reproduction, photosynthesis, genetics, allelopathic effects and integrated control. The weed can grow under relatively high temperature, light and humidity conditions and soil barrenness. The seeds of the weed are easily transmitted by wind, animals(insects etc.) and by long distance transportation or exchange of crop products infested with the weed seeds. It is expected that the distribution of yellow-top weed will be expanded to greater area (Beijing, Henan and Shandong province) in the next one or two decades in China. Greater attention will be paid to yellow-top weed studies by weed scientists and more effective and economical strategies will be available for uses in yellow-top weed control.