Abstract: Adhesively bonded bars have been widely used recently. The bond behavior of adhesively bonded bars is greatly different from that of ordinary bars in concrete. No analysis methods for adhesively bonded bars are presented in concrete structure code. The mechanism and failure mode of adhesively single bonded bars and group bonded bars in concrete subjected to tension have been investigated. The influence of parameters such as bonded materials and thickness, concrete strength, bond depth, group bars effect, etc, on the bond behavior has been discussed. The ultimate load carrying capacity of the bars under mixed bond-cone failure mode has been analyzed. Comparison with test results has been made. It has been shown that theory analysis is in good agreement with experimental results. The formulae presented in this paper can be used in engineering design.