The atmosphere-ionosphere response before 2008 Mw7.9 Wenchuan earthquake based on global positioning system (GPS), detection of electro-magnetic emission transmitted from earthquake regions (DEMETER), and National Oceanic and Atmospheric Administration—advanced very high resolution radiometer (NOAA/AVHRR) satellite data is analyzed. It is found that GPS total electron content (TEC) above the epicenter continuously decreased in the afternoon periods from 6 to 10 May but increased in the afternoon of 9 May. Contour analysis on ionospheric plasma using Instrument Sonde de Langmuir data onboard DEMETER satellite showed that electron density (Ne) and ion density (Ni) was also reduced from 6 to 10 May, the anomalous region mainly distributed in the south of the epicenter, conforming to the anomalous TEC area. The brightness temperature () from NOAA/AVHRR data, calculated by index method, shows a noticeable enhancement on the northwest side of the epicenter on 7 May, while ion temperature () from DEMETER data increased on 9 May with the order of . The energetic particle flux presents an obvious enhancement for the spectrum at 100 to 600 keV energy range on 6 May. Preliminary study suggests the perturbations of these parameters (TEC, Ne, Ni, , and ) before the Wenchuan earthquake may be related to the changes of vertical electric field in the atmosphere and ionosphere, induced by the enhancement of stress in tectonic regions and the electromagnetic signal propagation from the earthquake preparation area.