This paper investigates experimentally the deformation characteristics of the mono strand anchor head used in prestressed concrete bridge. Since the strains measurable in the anchor head are the axial and hoop strains, the deformation characteristics of the anchor head are examined by measuring these strains at various positions and according to the jacking force exerted on the prestressing strand. Moreover, the possibility to estimate the jacking force acting in the tendon based upon the measured strains and the corresponding error are evaluated.