  We present results of an improved analysis of the experimental data of the
EAS Cherenkov array Tunka-25. A new function to fit the Cherenkov light lateral
distribution LDF at core distances from 0 to 350 m has been developed on the
base of CORSIKA simulations and applied to the analysis of Tunka data. Two
methods to estimate the EAS maximum position have been used. The one is based
on the pulse FWHM, the other on the light LDF. We present the primary energy
spectrum in the energy range 10^15 - 10^17 eV. The use of the depth of the EAS
maximum to determine the mean mass composition is discussed.
