A　passive　harmonic　mode-locked　ytterbium-doped　fiber　laser　with　all-normal　dispersion　has　been　demonstrated.　The　mode-locking　mechanism　of　the　laser　is　based　on　the　interaction　between　semiconductor　saturable　absorber　mirror　and　nonlinear　polarization　rotation.　The　repetition　rate　of　the　laser　is　adjustable　from　7.91　MHz　to　31.65　MHz.　Via　the　chirped　pulse　amplification,　the　1　ps　mode-locked　pulse　at　the　fundamental　repetition　rate　of　7.91　MHz　is　compressed　to　720　fs　with　single　pulse　energy　of　12.6　nJ.