Densification behavior, microstructural evolution, and mechanical properties of hot-pressed specimens using $eta$-SiC and $alpha$-SiC powder with Al2O3 additive were studied. Beta-SiC powder was fully densified as 205$0^{circ}C$, but $alpha$-SiC powder was at 210$0^{circ}C$. The maximum flexural strength and the fracture toughness of the specimen hot-pressed using $eta$-SiC powder were 681 MPa and 6.7 MPa{{{{ SQRT {m } }}, and thosevalues of specimen hot-pressed using $alpha$-SiC powder were 452 MPa and 4.7 MPa{{{{ SQRT {m } }}, respectively. The strength superiority of specimen hot-pressed using $eta$-SiC powder was due to the finer grain size, and higher density. The higher toughness of specimen hot-pressed using $eta$-SiC powder than $alpha$-SiC powder than $alpha$-SiC powder was due to the crack deflection mechanism arised from the difference of thermal expansion coefficient between $alpha$ and $eta$-SiC phases which were co-existed in the sintered body.