【Background】Common ragweed （Ambrosia artemisiifolia L.） is a worldwide noxious weed and has successfully invaded several regions of Guangdong Province, China. 【Method】A.artemisiifolia′s distribution in Guangdong Province was surveyed with fixedpoint and line assessment methods. Seeds from Fugang County populations were collected for further studies on the growth and morphological development of the species. In greenhouse conditions, seeds were planted in a gradient of temperatures and germination rate were checked. Phenological events (e.g. first shoot, flowering, etc.) were recorded in natural occurrence habitats. 【Result】The surveys showed that A.artemisiifolia′s distribution encompassed the northern and northeastern parts of Guangdong Province, including Shaoguan, Qingyuan, and Meizhou City, as well as the eastern regions, such as Shantou and Shanwei City, and western regions of Zhaoqing and Zhanjiang. Up to now, it has not been found in Pearl River Delta. No dormancy was noted for the collected seeds of A.artemisiifolia. There were two peaks of germination occurrences in natural habitats: one in March to April, and another in November to December. It was therefore possible to observe plants at various growth stages anytime during the year. Morphologically, some plants formed stocky tuft plants while others, small shrubs. 【Conclusion and significance】A.artemisiifolia may be spreading towards the central and southern regions of Guangdong Province, and inevitably becoming a threat to agriculture and human health in Pearl River Delta.