The dependence of polarographic parameters on the pressure for the reduction of In(III), Cr(III), Cd(II), Pb(II), Mn(II), Co(II), Tl(I) in 0.1M KCl aqueous solution at the dropping mercury electrode have been discussed. In this experiment the temperature varied from $25^{circ}C;to;35^{circ}C$ and the pressure ranges from 1 atmosphere to 1,800 atmospheres. By increasing the pressure the reduction half-wave potentials of all metal ions are shifted markedly to more negative values and the diffusion currents of all metal ions become considerably larger. The slope of the linear relationship of E vs. log[$frac{id-i)}{i}$] become much larger with increase in pressure, which indicates more irreversible reduction. The temperature coefficient observed over the range of the temperature from $25^{circ}C;to;35^{circ}C$ are not sensitive with increase in pressure.