Risk assessment is an important process especially against the invasive alien species. The yellowlegged(black thorax) hornet, Vespa velutina nigrithorax Buysson, 1905 (Hymenoptera: Vespidae) is considered invaded into Busan, Korea in early 2000s, and now imposing increased threats to apicultural industry as well as to human and natural ecosystem. This paper reviewed the contemporary data on the biology, distribution, invasion pathway and socioecological risks and provided suggestions on management of the risk. Vespa velutina nigrithorax is a so-called bee hawking hornet specialized on predation of honeybee. It now distributes most of the southeastern part of Korean peninsula with the 10~20km/year spread. The Korean population was homologous to Zhejiang population of China implying the possible invasion source. It has a great potential to harm the Korean beekeeping industry and the ecosystem through the competition with the similar guild, the other 10 spcies of Vespa in Korea. Among those, smaller sized hornets such as Vespa analis or V. simillima simillam seemed under serious impact. Also because of the nesting propensity of urban area, public education and involvement are requested for protection against the hornet’s aggresiveness and also for monitoring the distribution and population expansion. Further research and public network would mitigate the potential risks.