The coronal slow shock has been predicted to exist embedded in large coronal holes at 4-10 solar radii. We use a three-fluid model to study the jumps in minor ion properties across a slow shock such as the coronal slow shock. We formulate the jump conditions in the de Hoffmann-Teller frame of reference. The Rankine-Hugoniot solution determines the MHD flow and the magnetic field across the shocks. For each minor ion species, the fluid equations for the conservation of mass, momentum and energy can be solved to determine the velocity and the temperature of the ions across the shock. We also obtain a similarity solution for heavy ions. The results show that on the downstream side of the slow shock the ion temperatures are nearly proportional to the ion masses for He, O, Si, and Fe in agreement with observed ion temperatures in the inner solar wind. This indicates that the possibly existing coronal slow shock can be responsible for the observed heating of minor ions in the solar wind. ¿ American Geophysical Union 1990