In order to reveal the atmospheric dynamic backgrounds of white back planthopper (WBPH),Sogatella furcifera, immigrations and establish the meteorological substructure of its catastrophes forewarning, based on the information of WBPH’s investigations of 69 plant protection stations covered the most of Chinese rice-growing areas in 2003, Chinese tempo-spatial patterns of WBPH′s populations was analyzed topographically under the software assistance of ArcGIS9.0. According to this analysis, 2 typical great immigrating events were selected. The observational meteorological data and T213 numerical simulation products covering these processes were obtained from the data accepted by a PCVSAT (PC Vary Small Aperture Terminal) station. These data were input into a model, MM5 3.2(The Fifth-Generation Mesoscale Model for version 3.2), and a set of atmospheric dynamical fields during these migrating and landing processes were simulated numerically and analyzed objectively. The results showed as followed: (1) The most important factor of atmospheric general circulation controlled and influenced the immigration of WBPH′s populations was the patterns and the tempo-spatial changes of potential height field on 850hPa isobaric surface. (2) There were relative coincident air streams with a northern exposure on 850hPa isobaric surface during the migrations northward of WBPH and there were concurrent airflows with a southern exposure on 925hPa isobaric surface during the migration southward. The regions with cyclonic shears of wind directions were advantageous to the taking-off and emigrating of the pest and the regions with anticyclonic shears of wind directions were favorable to the immigrating and landing on 850hPa or 925hPa. (3)The rainfall played an important dynamical threatening role in the landing processes of WBPH′s populations. Its effect in the landing processes of migration northward was stronger remarkably than the landing processes of migration southward. (4) The strong subsiding airflow on the vertical velocity field could compel WBPH′s populations to land cosmically. It testified that vertical airflow threatening is a principal atmospheric dynamical mechanism of the catastrophic immigrations of windborne pests.