Submicron ${alpha}-SiC$ powder with $Al_2O_3$ addition was hot-pressed under the controlled heating and pressurizing schedule. $SiO_2$ layer on ${alpha}-SiC$ powder was effective for the sintering of ${alpha}-SiC$ powder when $Al_2O_3$ was used as an additive. Applying of pressure under the controlled schedule accelerated the rearrangment of SiC grains, yielding 98% of theoretical density of SiC even at $1900^{circ}C$. Flexural strength of the specimen containing 2 wt% $Al_2O_3$ was increased as increasing the hot-pressing temperature up to $2050^{circ}C$ and maximum value was 800 MPa, while the flexural strength of the specimen containing 10 wt% $Al_2O_3$ was decreased as increasing the hot-pressing temperature above $2000^{circ}C$ due to the formation of continuous grain boundary phase. Fracture toughness of the specimens was in the range of $3.5~4.5;MNm^{-3/2}$ regardless of the amount of $Al_2O_3$ addition.