Abstract:Mikania micrantha is considered to be one of the most serious tropical and subtropical weeds which is now widely distributed in Guangdong Province and mainly in Pearl Delta. Of the 51 counties and cities investigated in Guangdong, 24 were found to have its distribution. The habitat of this weed has a wide range: among natural vegetation, in cultivated land, orchards, nurseries, vegetable plots, forest plantations, roadside, plant hedge, refuse dump, and under sun or shade, in dryland or moist soil．The climatic condition，harmful effect，and the control of the weed are analysed and discussed．