A driving mechanism for a slide rail assembly with a first and a second rails includes a first driving device, a locking device, a swing member and a second driving device. The first driving device includes a first elastic member and a first base. The first elastic member accumulates a first driving force when the swing member abutting against a locking part of the locking device. The second driving device is mounted to the second rail and includes a second base movably connected to the first base, a blocking member movable in a guiding section of the second base, and a second elastic member. When the second rail and the second base are moved from a retrieve position toward an open position relative to the first rail, the blocking part abuts against a portion of the guiding section for allowing the second elastic member to accumulate a second driving force.