Abstract:Rorippa amphibia (L.) Besser originates in most part of the Europe. It was also distributed in Caucasia, Middle Asia, North Africa and North America, even in New Zealand. Recently it was found in Dalian, Northeast China, mainly distribute in lawn of the city. The species was mainly exported from Canada and United States, so it is easily inferred that Rorippa amphibia (L.) Besser was incidental from that area. In addition, the taxonomic characters and latentmenace of the species were introduced. Voucher specimens are preserved in Dalian Natural Musem (DNHM).