This paper aims to reveal the effect of atmospheric low temperature stress on the initial immigration of brown planthopper, Nilaparvata lugens (Stål) in China and conduct effectively warning of the early immigration of the populations from overseas. In this study, the migratory trajectories and source areas of N. lugens were deduced based on the statistics of the annual immigration beginning dates and first immigration peak dates of N. lugens during the period from 2000 to 2017 in the rice-growing regions of South and Southwest China. The influence of atmospheric temperature field on the migrating processes was analyzed and the difference of the impact of atmospheric low temperature stress on N. lugens' initial immigrations between the different rice areas in different years was compared. The results showed as follows: (1) in recent years, the immigration beginning dates of N. lugens into China were earlier than before. The immigration beginning dates into South China were earlier than those in Southwest China in general. The dates of early initial appearance in South China might be related to the northward migrations of N. lugens' population over winter. (2) Initial overseas insect sources of N. lugens in Southwest China were mainly from Myanmar. In South China, the main sources of the initial immigrations in the year came from the middle and northern parts of Vietnam and Laos. (3) The temperature distribution in the prevalent migratory layers showed that the probability of low temperature barriers occurring during the initial immigrations of N. lugens was about 54.4%. The average low temperature stress intensity was 13.45 ℃ and the average cooling range was 1.88 ℃. Among them, the low temperature stress was more significant in South China (the occurrence probability was 58.3%, the average intensity was 13.18℃), and more obvious in the immigration beginning dates (the occurrence probability was 70.6%, the average intensity was 12.53℃).