The effect of the active carbon texture on the ruthenium dispersion and catalytic properties of the Ru/C systems in ammonia synthesis and decomposition has been discussed. It has been shown that the mean size of ruthenium crystallites determined by the chemisorption methods is the lower, the more developed the carbon texture is. Caesium was shown to be an unusually efficient promoter of the ammonia decomposition reaction, considerably more efficient than barium. The system co-promoted with barium and caesium proved to be more active, in turn, in the NH3 synthesis than the singly promoted Ba-Ru/C or Cs-Ru/C specimens.