A tape cartridge capable of preventing emission of vibrating sounds and occurrence of abrasion at a usage time when a reel hub unit rotates at a high rotating speed. The tape cartridge has a single reel hub unit rotatably accommodated in a case and having its periphery wound with a tape-shaped recording medium, a brake lock member including an engaging portion for engaging a reel hub unit to restrict rotation of the reel hub unit when in non-use, and a flat surface bearing portion provided substantially at a central part of the brake lock member, wherein the central axis of said flat surface bearing portion of the brake lock member is parallel with and offset from the rotating central axis around which said brake release member rotates together with said reel hub unit.