Abstract: According to the strain value along the anchor length based on the pull out test of the recycled aggregate concrete, it was calculated the bond stress and summarized the rule of the bond stress along the anchor length. The changing principal of the chemical joint strength,the mechanical linking strength and the friction force along with the pulling force was discussed. The load transfer unit and load transfer mode theory was firstly proposed. And the theoretical model of the bond stress along the anchor length was given, whose results agreed with the experimental results. Finally,it was defined the asymmetry coefficient of bond stress and analyzed the influence of factors on the distribution of bond stress at ultimate state.