Experimentally, the electron drag effect on carbon nanotube surface in flowing liquids was investigated. It was found that electric current could be generated in metallic carbon nanotubes immersed in the liquids. Carbon nanotubes were synthesized on Si substrate by hot filament chemical vapor deposition. The experimental results showed that the flow-induced current on the surface of carbon nanotube films was closely depended on the flow rate, concentration, properties and temperature of liquids. The flow-induced current was increased with the increasing of flow rate, concentration and temperature of liquids. The obtained results were discussed in detail.