A toothbrush capable of seeing dental plaque comprises a main body, a detecting light source, a battery, and a control circuit. The main body includes a head and a handle. The head has a plurality of bristles and is replaceable relative to the handle. The detecting light source is arranged at the handle of the main body and emits a wavelength ranged from 400 nm to 700 nm. The battery and the control circuit are arranged at the handle of the handle of the main body. The control circuit is electrically connected with the battery and the detecting light source.
