Purpose : This study aimed to find out the effects of treatments on the surface of Zirconia. Methods : To this end, we selected six treatments that have been used widely: steam cleaning, 2bar & 6bar sand blasting, grinding by green stone point, grinding by diamond bur, and grinding by diamond bur with water spray. Results : The results of our study showed that monoclinic rate increased from all six treatments. Monoclinic rate varied by treatments, ranged from 0.6% (steam cleaning) to 6.5% (6bar sand blasting). These values from all six treatments were below ISO 13356 standard, which is 25%. Also, we found that two treatments (green stone point and diamond bur) increased roughness of surface of Zirconia. Conclusion : This study concluded that phase changes of Zirconia were not significant by using six treatments we employed.