[en] An attempt has been made to select muons in Extensive Air Showers (EAS) by means of tracking telescopes and reconstruct their apparent height of production along the shower axis. By this way a reconstruction of shower longitudinal development in the Earth atmosphere can be obtained. Results indicate that the only information of muon arrival direction is not enough for the correct reconstruction of shower longitudinal development, mainly because of the distorting effect of the Earth geomagnetic field and multiple coulomb scattering by air nuclei