A slide rail assembly is disclosed and includes a first rail, a second rail and a fitting member. The second rail and the first rails are movable relative to each other. The fitting member is detachably mounted to one of the first rail and the second rail. The fitting member is configured to block the second rail as a blocking member, such that the second rail is located at a same position when retracted relative to the first rail. Alternatively, the fitting member is configured to adjust the position of the second rail as an adjusting device, such that the second rail can be located at different positions in response to the adjustment of the adjusting device when retracted relative to the first rail.