Fractions of proton, helium, middle and heavy nuclei in primary cosmic rays at energy 10**16eV

Classification of gamma-hadron families, registered by the Pamir collaboration, on four groups of nuclei (P, He, middle and heavy), responsible for their generation, is made, and fractions of families in each of the groups are estimated. Results show, that below the knee of the energy spectrum the chemical composition of primary cosmic rays remains close to the normal one.