The evaluation of the pull-out experimental result of the steel reinforcing bar on fly ash-based geopolymer concrete prism is presented in this study. A single reinforcing bar with the nominal diameter (db) of 13mm was pulled out from the geopolymer concrete prism. Three sizes of geopolymer concrete prism were presented, 100x100x200, 150x150x200, and 180x180x200 m3. Hence the ratio of cover thickness to diameter of the bar (c/db) were 3.4, 5.4, and 6.6. The effects of bond length (Ld) that were 3db, 5db, and 7db were investigated. The results showed that the bond length changed the mode of failure. The pull-out failure occurred on the specimens with the short bond length (3db), splitting failure occurred on the long bond length, and the bar ruptured on the large specimens with longer bond length (7db). The highest of maximum pull-out load and the bond strength obtained were 77.58 kN and 42.13 MPa, respectively. The maximum pull-out load increased with increasing the bond length. The bond strength decreased as the bond length increased