Introduction For the last decades, the increased understanding of the detrimental health and environmental effects of atmospheric aerosols gave rise to policies and directives aimed at controlling ambient concentrations of particles, such as PM10 and PM2.5. Particle pollution is partly due to local anthropogenic source emissions. Meanwhile, pollution advection from different geographical origins can also contribute to these concentrations, but their corresponding impacts in different seasons are not yet clear (Hu et al., 2014). Within this context, PM2.5 and its main chemical species were monitored from 2011 to 2018 at 5 French background monitoring stations belonging to the MERA network (French contribution to the EMEP network) in order to investigate sources and geographical origins influencing PM2.5 variability at interannual/seasonal scales. Material & Methods Hourly PM2.5 mass concentrations (Figure 1) were measured by TEOM-FDMS, FIDAS or Beta gauges. PM2.5 samples were collected on a 24-h basis every six days using sequential HVS filters. The chemical analysis included ionic and carbonaceous PM2.5 main components along with some organic tracers (sugar anhydrides, polyols and organic acids - only for the years 2013 and 2014). PM2.5 chemical compositions were compared to those of 15 other EMEP Europe-wide sites in order to study the site representability. Trends of species concentrations were determined using the Mann-Kendall and Theil-Sen tests (Figure 1). Interrelations between PM2.5 main components, organic tracers and meteorological parameters are investigated to better assess local sources versus long-range transported contributions. Potential geographical origins were identified and apportioned using climatology clustering and two complementary trajectory-based statistical models as presented in Waked et al. (2018). Conclusions PM2.5 chemical compositions of the 5 French stations are consistent between each other and with other EMEP sites, highlighting their background representativeness at national and even European scales. This finding also suggests that they were globally influenced by similar sources and/or processes. Decreasing annual trend in PM2.5 mass concentrations (Figure 1) partly results of decreasing annual trend in EC and primary/secondary inorganic PM2.5 component concentrations while annual organic matter concentrations have increased. Rising trend in annual OC/EC ratios suggests possible increased secondary organic aerosol contributions to PM2.5 concentrations. The clustering analysis of PM2.5 speciation and related climatology better explains PM2.5 variability at interannual/seasonal scales (e.g. contrasted climatological situations which can influence advection of air masses loaded with source emissions from Central European areas to French receptor sites).