Abstract: Disclosed is a shelf support construction including an elongated, rigid, hollow, box channel adapted for attachment to a wall or other surface which is normally vertically positioned with an open slot to receive a shelf support bracket. The bracket has a rear portion engageable in the interior of the box channel and terminating in fingers alternately bent to the right and to the left of the bracket's plane, to grip the inner side walls of the channel. Projecting stops are formed on the fingers to bear against the flanges defining the slot to prevent dislodgement of the bracket from the channel. An adjusting sleeve is provided which slides on the bracket to compress the fingers into locked and unlocked positions relative to the channel when it is desired to change the position of the bracket on the channel or effect its removal by sliding same out of the channel from its open upper or lower end. The ends of the fingers can be serrated to engage the inner side walls of the channel.