Critical heat fluxes are obtained in subcooled pool boiling of mixtures with alcohol and water by burning out stainless steel plate heater. The critical heat fluxes change with mass concentration of alcohol. For the mixtures of polyhydric alcohols, 1-butanol and 2-propanol, the maximum critical heat fluxes are about 200 percent higher than that of water. In subcooled flow boiling of ethanol-water and 1-butanol-water mixtures in a horizontal rectangular channel, microbubble emission boiling occurs in transition boiling and the heat fluxes are about 50 percent higher than water at same superheat of heating surface. The maximum heat fluxes of the mixtures reach 8 MW/m^2 at 40K of liquid subcooling and 0.5m/s of liquid velocity.