We formulate empirically the rapidity density distribution of produced particles in multiple particle production. We assume several emitting centers, distributed on the rapidity axis, from which the produced particles are emitted isotropically with energy distributed in the inverse-exponential form. The formula includes four parameters, the values of which are determined to reproduce the experimental data of the average value of the transverse momentum and the pseudo-rapidity density distributions at various incident energies. The formula describes well the pseudo-rapidity density distributions in a wide range of energy (root s = 22.4, 53, 200, 546, 630, 900 and 1800 GeV), by adjusting the values of the parameters. The transverse momentum distributions, however, are not described well at large values of the transverse momentum. The multiplicity and the inelasticity of produced particles are discussed at high energies up to root s = 447 TeV (E(0) = 10(20) eV), based on the energy dependences of the parameters. The inelasticity becomes small at high energies, less than 0.1 at root s >= 5x10(4) GeV, which is not consistent with the predictions of the existing models. The pseudo-rapidity density distribution of the produced particles at LHC energy (root s = 14 TeV) is compared with those distributions obtained by other models.377