The　study　of　hysteresis　can　be　traced　back　to　the　19th　century.　The　key　characteristics　of　hysteresis　are　rate　independence　and　rate　dependence.　A　typical　system　with　hysteresis　characteristics　is　the　reducer.　In　the　industrial　sector,　the　hysteresis　phenomenon　of　a　reducer　is　often　illustrated　by　the　lost　motion,　which　is　always　consistent　with　the　rate　independence　by　default.　In　the　paper,　a　hysteretic　model　of　reducer　considering　geometric　errors　is　established.　Theoretically,　the　hysteretic　characteristics　of　the　reducer　are　found　to　mostly　maintain　the　rate　dependence　rather　than　the　rate　independence.　The　loading　rate　will　lead　to　a　change　in　the　hysteretic　characteristics　of　the　reducer,　thereby　affecting　the　lost　motion　test　and　the　design　of　the　reducer.　Through　further　experimental　research,　it　is　verified　that　the　dependence　of　the　loading　rate　will　have　an　impact　on　the　results　of　the　lost　motion　test,　and　different　gear　materials　have　different　effects　on　the　dependence　of　the　loading　rate.