In recent years, heat dissipation rates in personal computer, power devices and laser diodes have been increasing, and water-cooling technique is becoming to be used in electronic equipment cooling. When fins cannot be mounted on the heated base plate surface in the liquid channel because of manufacturing constraint, turbulence promoter is usually used in the liquid channel. We developed a heat sink with a wavy turbulence promoter facing heated base plate as a thermal enhancement technique in the liquid channel. The heat transfer coefficient of the base plate facing wavy turbulence promoter was 20000-30000W/ (m2·K). The heat transfer performance of the heat sink with a wavy turbulence promoter facing heated base plate was 3 or 4 times larger than the smooth surface channel.