【Background】The cotton mealybug Phenacoccus solenopsis Tinsley is an invasive insect pest, firstly reported in 2008 in the Yunnan Province, China. Although it is known to be spreading rapidly, there is still a lack of systematic assessment. 【Method】From March of 2010 to March of 2013, 16 cities including 72 districts were surveyed to study distribution and damage of P.solenopsis in the Yunnan Province. 【Result】The results showed that P.solenopsis was distributed in 10 sites belonging to 8 districts, Funing, Jinghong, Menghai, Mangshi, Yuanyang, Mengzi, Longyang, Huaping, Yongren, and Lushui. The mealybug was found on 19 host plant species representing 14 families. Of these 19 species, 12 have not been reported previously as host plants for mealybug. Three species of natural enemies were also found. 【Conclusion and significance】Solenopsis mealybug showed scattered distribution in the Yunnan Province. The damage caused by the species was also scattered in the province with no damage to cash crops. The study can provide fundamental information for inspection and quarantine of P.solenopsis mealybug in the Yunnan Province.