Nilaparvata lugens (N. Lugens) is one of the pests which have a large detrimental impact on rice production in Asia. Long-distance migration and population distribution are highly dependent on large-scale atmospheric circulation and local weather condition. The observational data of light-trapped pests from 1979 to 2015 were analyzed to quantify the impact of large-scale atmospheric circulation on southward migration of N. Lugens. A typical heavy event of southward migration occurring in the major rice-growing regions of the southern China from September 30th to October 7th, 2009 was presented to discuss the impact of different weather conditions on immigration population of N. Lugens in different rice-growing areas in South or Southeast China. The event was characterized by large-range precipitation in South China. A large amount of precipitation and high temperature were observed in the coastal regions of Fujian Province, South Jiangxi Province, and Southwest Hunan Province. In contrast, the rainfall was much less and temperature was relatively lower in the middle and north parts of Jiangxi Province compared to other regions and the rainfall was sporadic and the temperature was high in Hubei Province. As a result, the amount of light-trapped N. Lugens was the largest in the coastal regions of Fujian Province, South Jiangxi Province, and Southwest Hunan Province, and the least in the middle and north parts of Jiangxi Province. The trapped amount in Hubei Province lied in between the two previous group regions. In this study, an online-coupling system of the Weather Research and Forecast Model (WRF) with FLEXible PARTicle dispersion model (FLEXPART) was utilized to simulate the meteorological conditions and to calculate the trajectories and the parameters associated with N. lugens' migration. ArcGIS (a geographic information system software) was used to perform detailed spatial analysis and the Vincenty's formula was applied to the calculation of azimuth and distance of migration. Several important results were identified from the study. First, meteorological factors including wind fields, rainfall, temperature, humidity conditions played vital and different roles in the immigration and land-falling of N. lugens in different areas during different periods and contributed the discrepancy of temporal and spatial distributions of N. lugens' migration population. Second, N. lugens tended to immigrate toward the warm and humid areas. Migrating direction and migrating distance were determined by wind direction and wind speed of prevailing winds, respectively. Third, the immigrating amount of N. lugens was small at the beginning but can be accumulated to a significant level in a short time period. Fourth, within the certain range of air temperature, air humidity is the key parameters in determining migration population and temporal-spatial distribution. Immigrating N. lugens were concentrated in the regions with 2 m temperature higher than 26℃ and the relative humidity higher than 70% at the 925 hPa level whereas very few immigrating N. lugens can be observed in the region with 2 m temperature lower than 24℃ and the relative humidity less than 50% at 925 hPa level.