In　this　paper,　a　ultrasonic　method　for　measuring　the　cylindrical　roller　bearing　lubricant　film　thickness　distribution　is　presented.　And　the　test　bench　and　the　high-frequency　ultrasound　signal　acquisition　and　analysis　system　have　been　designed　and　initially　built　for　the　real-time　measurement　of　the　cylindrical　roller　bearing　lubricant　film　thickness　distribution　in　the　industry　condition.　The　minimum　lubricant-film　thickness　measured　by　50MHz　broadband　ultrasonic　probe　are　described　at　high　radial　loads　and　low　rotary　speeds　for　proving　the　feasibility　and　the　reliability　of　the　system.　©　2013　IEEE.