Comet 67P, the target of Rosetta mission, was observed in the visible and near-IR spectral regions during its perihelion approach. The observations were performed in four epochs, at heliocentric distances varying from about 3 to 1.4 AU, i. e. in the same range of the Rosetta mission. The aims of the observations were the study of the dust coma and its evolution with the distance from the Sun. Results show the presence of a narrow tail and a faint coma at 3 AU. Later the tail disappeared and an intense dust coma started developing. The coma showed a strong increase of density in its inner part, close to the nucleus. This increase cannot be explained with the presence of sublimating grains, because the sublimation rate appears to decrease as the comet approaches the Sun. A possible scenario is a coma constituted by big grains that expand very slowly, with a projected velocity of the order of 0.5 m/s. In the presentation we discuss all possible alternatives, showing that the latter scenario is the most probable.