Cabbage whitefly, Aleyrodes proletella (L.), was found for the first time in Chaoyang, Beijing, China in July 2012 on Ixeris sonchifolia Hance. This whitefly was found in Urumqi and Turpan, Xinjiang, China in August 2013 on blooming Lactuca sativa L. and I.sonchifolia Hance. In this paper, we describe the damage, host plant species, distribution areas, morphological characteristics, natural enemies and method of dispersal of this whitefly species. In addition, we analyze the current trends of dispersal of the species and the most threatened areas in Mainland China.