Purpose: Densification and mechanical properties of dental zirconia ceramics were evaluated by different sintering methods. Materials and Methods: Y-TZP zirconia block(Kavo $Everest^{(R)}$ ZS blank, Kavo dental GmbH, Bismarckring, Germany) was used in this study. Sintering were performed in heat sintering furnace and microwave sintering furnace, and then experimented and analyzed on a change in densification according to the sintering time, a change in densification according to thickness, flexural strength and micro-structure in zirconia specimens. Results: Microwave sintering was very effective in considerable mechanical properties such as flexural strength and bulk density was drastically increased than conventional electric heating method. It is also shown that microwave sintering time was faster and more economical than common method to be present in qualities which equal or exceed. Conclusion: It will be important to seek the accurate sintering condition of dental zirconia by microwave sintering method and the continuous research is necessary for the study of relationship between sintering methods and mechanical properties.