An angular velocity of flow sensor for liquids based on single-walled carbon nanotube thin films is presented. The carbon nanotubes in this study were fabricated on Si substrate by hot filament chemical vapor deposition (CVD). The experimental results showed that the flow-induced current on the surface of carbon nanotube thin films was closely depended upon the angular velocity, concentration, properties and temperature of the liquids. The current increased with increasing angular velocity, concentration and temperature of the liquids. In this study, the liquids such as water, NaCl solution and other electrolyte were flowing over the sensor. The results obtained were also discussed. The theoretical and experimental studies have shown that there was electronic friction and electron drag effect of carbon nanotubes in flowing liquids. This effect in carbon nanotubes can be used for a new flow sensor.