[en] Electron mass collision stopping power is a fundamental physical quantity describing energy loss process in matter of ionizing radiation. With increasing of accuracy in dose estimation for radiation dosimetry, it is recommended that restricted stopping power for Bragg-Gray cavity theory would be used. However, there are not enough data of the restricted stopping power for the material which we often used as a phantom. To make the calculation of restricted mass collision stopping power for electrons, we carried out the correction for density effect using either Sternheimer and Peierls or Hiraoka et al correction method. Electron mass collision stopping power estimated for 9 tissue substitutes and air agrees within 0.3-0.5% compared with ICRU report 37. (author)