[en] The CSES satellite, developed by Chinese (CNSA) and Italian (ASI) space Agencies, will investigate iono-magnetospheric disturbances (induced by seismicity and electromagnetic emissions of tropospheric and anthropogenic origin); will monitor the temporal stability of the inner Van Allen radiation belts and will study the solar-terrestrial coupling by measuring fluxes of cosmic rays and solar energetic particles. In particular the mission aims at confirming the existences (claimed from several analyses) of a temporal correlations between the occurrence of earthquakes and the observation in space of electromagnetic disturbances, plasma fluctiations and anomalous fluxes of high-energy particles precipitating from the inner Van Allen belt. CSES will be launched in the summer of 2017 with a multi-instruments payload able to measure: e.m. fields, charged particles, plasma, TEC, etc. The Italian LIMADOU collaboration will provide the High-Energy Particle Detector (HEPD), designed for detecting electrons (3–200 MeV) and proton (30–300 MeV)), and participates to develop the Electric Field Detector (EFD) conceived for measuring electric field from ∼DC up to 5 MHz. - Highlights: • On Summer 2017, the CSES satellite will be launched to study the near-Earth e.m., plasma & particles environment. • The scientific objectives are: litho-atmo-ionosphere coupling, seismic precursors, solar-terrestrial physics & cosmic rays. • For CSES, we have built a high-energy particle detector (HEPD) and an electric field detector (EFD). • The article introduces the scientific background, the objectives of CSES and the satellite layout. • We discuss the features of HEPD and EFD, the calibration procedures and the laboratory tests.