Abstract: Multi-pulse generation based on a narrow-band filter in a passively mode-locked erbium-doped fiber ring laser is investigated experimentally. The low threshold multi-pulse is easily achieved by inserting a narrow-band fiber Bragg grating (FBG) filter into the laser ring cavity to limit the lasing bandwidth. Depending on the pump power settings, the number of output pulses can be discretely tuned one by one. Moreover, the chaotic state of multi-pulse operation is also observed. The experimental results are further confirmed by the numerical simulations, which prove that a narrow-band filter could greatly enhance the multi-pulse generation.