The present paper gives an expression of the effective phonon spectrum a2F(ω),spectrum area λ/2 and electron-phonon coupling constant A of the metal with valence Z in terms of a few parameters, such as average electronic radius rs, Ion mass M and sound velocity vj. Using the formula of Dynes, we have calculated the superconducting transition temperature Tc for matalic hydrogen, lead and niobium. It is shown that matalic hydrogen has λ = 2.55 and Tc = 162 K at zero pressure.