Silica sol-gel glasses doped with Eu3+ ions were obtained by different preparation techniques. The absorption, emission and excitation spectra of the obtained glasses were measured in the range of 77-300 K. The energy level diagrams of Eu3+ ions were derived. An intensity analysis of f-f transitions was performed. In particular, polymeric structure behaviour of europium compounds entrapped in silica gels glasses was temperature controlled during the preparation of glasses. Their optical properties were investigated