Some novel methods to get the optical pulses at repetition rate (fp) integer multiples of the RF drive frequency in actively harmonic mode-locked erbium doped fiber laser (AHML-EDFL) are reported. The character of the nonlinear modulation is analysed. The mechanism of high-repetition rate pulses generated from AHML-EDFL in particular, the influence of modulation degree on pulse train are discoussed.