In August 2017, during field surveillance in Yili, Xinjiang, China, we found an infestation of lepidopteran larvae on field-grown tomato plants. The plants displayed serious infestation, mined leaves and attacked fruits. This lepidopteran was identified as Tuta absoluta (Meyrick), a species native to South America. This species had been introduced to Spain in 2006. By May of 2017, it has appeared in more than 80 countries in South America, Europe, Africa, Central America and Asia and has caused serious damage to tomato production world-wide. The maximum yield losses caused by this species can reach 80%-100%. It is the first record of T. absoluta in China. In this paper, the morphological characteristics of T. absoluta and its damage is described. In order to prevent further spread of this new invasive insect pest in China, prevention measures, including plant quarantine, nation wide investigation of its distribution, studies of its biological and ecological performance, natural enemies and their control efficacy, detection and monitoring techniques, are proposed. The information provided in this paper should be useful in facing up to the pressures from the South American tomato leafminer on the safety of Chinese agriculture.