The objectives of the 209 project “NDACC Antarctic” consist in long term monitoring associated to process and climatological studies on both the particle population (aerosols, cirrus, Polar Stratospheric Clouds – PSC) and chemical composition (including stratospheric ozone) of the Upper Troposphere / Lower Stratosphere. The global thematic is the stratospheric ozone chemistry and depletion, in a changing climate context. Consequences on UV-B radiation on ground, as well as ozone interactions with climate, especially concerning the impact of greenhouse gases increases are also investigated. A set of instruments dedicated to the measurements of clouds occurrence and physical characterization, and ozone, along with the parameters involved in its chemical equilibrium is currently implemented on the French stations Dumont d’Urville, Kerguelen and Concordia. These instruments are: UV-Visible spectrometers, UV-B broad-band detector, balloon ozone soundings and lidar (Rayleigh/Mie/Raman). The observed variables are ozone, total column and vertical profiles, aerosols and PSC profiles, temperature, nitrogen dioxide and erythemal UV-B. This observatory program is part, at the French level, of the Observing Service NDACC-France.