Soft X-ray absorption experiments have been performed on industrial cobalt containing catalysts known to be effective in the Fischer-Tropsch synthesis. Firstly, we have studied a set of reference compounds CoO, SiCo2O4 and Co3O4 and numerical simulations based on the multiplets theory have been done in order to simulate their Co L-III,L-II absorption spectra. Then, Co L-III,L-II absorption spectra obtained on two Co based catalysts are discussed.