Abstract:An equipment and procedure are introduced for measuring the hydration temperature of wood-cement-water mixture. The effect of 38 wood species on the exothermic reaction of ordinary Portland cement was studied by this procedure. All the species tested are divided into two groups. 24 species includied in the first proup show a rather moderating influence on the hydration reaction of cement, and a peak of reaction temperature appears within 24 gours for each species. However, the other 14 species inhibi cement hydration completely. According to the maximum temperature o hydration and the time required to reach this temperature, the suitability of each species in the first group is estimatod when used as raw material for production of cement particleboard.