Longitudinal Development of Showers in the Energy Region of 10**15 10**17 eV

The longitudinal development of showers in the energy region of 1015 ÷ 1017 eV has been reconstructed by using the lateral distribution of EAS Cherenkov light and zenith dependence of the parameter Ns at the fixed energy. Thereby, the adaptive method algorithm in solution of the inverse tasks is used. Taking into account it, the absorption path lengths of particles in a shower at a different stage of its development have been found. This parameter can be used in testing of the hadron interaction models at E0 > 1015 eV and the mutual calibration of all compact EAS arrays.