Abstract：Y 2 O 3 -doped Al 2 O 3 transparent ceramics have been successfully fabricated by microwave sintering at the lowest temperature. Compared to vacuum sintering processing, the microwave sintering needs a lower sintering temperature and shorter dwelling time to get highly dense Y 2 O 3 -doped Al 2 O 3 transparent ceramics with finer grain size, higher mechanical and better optical properties. As a result, it is concluded that the low temperature microwave sintering has obvious advantages over the conventional sintering method in preparation of transparent Al 2 O 3 ceramics.