Abstract: Objective: The aim of the study was to evaluate the effect of a new zirconia primer on bond strength between resin composite and zirconia. Methods: 32 zirconia blocks were manufactured and randomly divided into 4 groups and received different surface-treatments. Group A: alumina sandblasted; Group B: alumina sandblasted followed by silica coating via sol-gel process combined by applying silane couple agent; Group C: alumina sandblasted followed by applying a ceramic primer contained 10-MDP monomer; Group D: alumina sandblasted followed by applying a new zirconia experimental primer. 32 light-cured composite resin cylinders were prepared and bonded on the zirconia discs using a conventional Bis-GMA based resin cement. Then, shear bond strengths (SBS) and modes of failure were determined. Scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used for characterization of zirconia treated by the experimental primer, and FTIR was used for characterization of the experimental primer. Results: According to statistical analysis, group A presented the lowest SBS values, while group D presented the highest mean SBS values. Conclusion: Using of the new zirconia experimental primer increases the short-time bond strength of zirconia.