Pitting　and　micropitting　are　the　two　main　gear　rolling　contact　fatigue　modes.　It　is　widely　accepted　that　micropitting　will　lead　to　pitting;　however,　the　relationship　between　pitting　and　micropitting　life　needs　further　investigation.　In　this　work,　micropitting　and　pitting　tests　were　performed　on　an　FZG　back-to-back　test　rig　using　standard　FZG　PT-C　and　GF-C　gears.　The　gear　tooth　profile　change　due　to　micropitting　and　pitting　damage　was　measured　in　situ　in　the　gearbox　using　a　profilometer　after　each　test.　The　gear　surface　roughness　parameters　were　calculated　from　the　measured　tooth　profile.　A　Gaussian　low　pass　filter　with　cut　off　length　lambda　c=0.8　mm　was　applied　to　the　measured　tooth　profile　to　obtain　the　waviness.　The　calculated　roughness　parameters　and　the　obtained　tooth　profile　with　waviness　for　each　test　were　imported　into　the　KISSsoft　software　to　calculate　the　contact　stress　and　specific　film　thickness　at　the　corresponding　load　stage.　Experimental　results　show　that　smooth　gear　surface　can　reduce　or　even　avoid　micropitting　damage,　but　could　lead　to　a　reduction　in　pitting　life.