In this study, the effects of four types of primer for a commercial zirconia adhesive system on the contact angle, bond strength, and bond durability were examined using a polished and/or sand-blasted zirconia surface.The polished zirconia surface was conditioned with Ceramic PrimerⅡ, Monobond Plus, Clearfil Ceramic Primer Plus, or Tokuyama Universal Primer. The contact angle of a waterdrop to the treated zirconia surface was measured before and after tetrahydrofuran wiping. Next, the bond strengths of the zirconia adhesive system to the polished and sand-blasted zirconia surface were measured with or without primer treatment. As a result, the contact angles differed among primers for each zirconia adhesive system. The primer increased the initial bond strengths to the polished and sand-blasted zirconia surface. With the exception of Ceramic PrimerⅡ, the other three types of primers showed maked decreases in the bond strength of the resin during the thermocycling process.It is concluded that there is a good correlation between the contact angle of a waterdrop to the primed zirconia surface and the initial bond strength of resin to the polished or sand-blasted zirconia surface treated with a primer.