In order to investigate the interaction of water mist with pool fires, a series of measurements and observations were conducted. Fire source is a small-scale circular stainless steel pan with heptane, ethanol and kerosene. The radiation spectra of the flames were measured by a monochromator system and the radiant heat flux were obtained by a thermogage before and after the application of water mist. At the same time, a Thermal Video System (TVS) was used to visualize the thermal field of the flame. These results show that in the case of heptane and ethanol, the flames was suppressed to less scale and the temperature and radiant heat flux decreased rapidly due to fuel surface cooling, oxygen displacement and heat radiant attenuation of the application of water mists. But in the case of kerosene, the results are different from the previous one. For instance, at the beginning of the injection of water mists, the kerosene flame was enhanced to larger scale, temperature and the radiant heat flux increased. These results maybe caused by more soot particles which were produced during the combustion of kerosene flame, because the particles can influence the penetration of mists into the plume and arrival at the fuel surface.