we　report　three　types　of　pulse　generation　in　Yb-doped　nonlinear　polarization　rotation　mode-locked　fiber　lasers　in　all-normal-dispersion　regime　through　simulation,　including　dissipative　soliton,　dissipative　soliton　resonance　and　noise-like　pulse.　We　distinguish　the　different　conditions　of　generating　such　different　pulses　by　analyzing　the　transmission　curve　of　saturable　absorber,　which　plays　a　key　role　in　pulse　shaping.　(C)　2015　Optical　Society　of　America