  We report hydrostatic pressure study on the Rashba-type noncentrosymmetric
superconduc- tors CaMSi3 (M= Ir, Pt). The temperature dependence of the
resistivity for both compounds is well described by the conventional
Bloch-Gr\"uneisen formalism at each pressure. This fact suggests that
electron-phonon scattering is dominant in these compounds. The superconducting
critical temperature Tc decreases by pressure as \sim 0.2 K/GPa above 0.41 GPa
to 2 GPa for both compounds. This behavior of Tc can be explained with a modest
decrease of the density of states based on the conventional BCS theory.
