Thermodynamic properties and electrical conductivity measurements of nonideal plasmas of hydrogen were carried out under multiple shock compression up to 1.5 Mbar. An abrupt increase of the electrical conductivity (by five orders of value) was registered starting at the density0.3÷0.5&hthinsp;g/cm3.This electrical conductivity value approaches∼103&hthinsp;&OHgr;−1&hthinsp;cm−1which is near to the liquid metal values. The data obtained are described by the nonideal plasma model taking account of the increase of number of conductivity electrons due to the “pressure ionization.” ©2000 American Institute of Physics.