The structure and the working principle of the retard-bonded prestressing tendon were introduced.The cracking moments,ultimate moments,crack distribution and load-deflection graphs of retard-bonded post prestressed concrete beams were studied through the experiment of 3 beams.The experimental results were compared with the theoretical and experimental results of bonded and un-bonded prestressed concrete beams,by which the bending law of retard-bonded post prestressed concrete beam was obtained and can be referenced in the designing of retard-bonded post prestressed concrete beams.