We fabricated the in-situ $MgB_2$ wires using the powder-in-tube method and investigated the effects of sintering temperature and SiC contents on the microstructure and superconducting properties. Pure $MgB_2$ wires and 5, 10, 20 wt.% SiC doped $MgB_2$ wires were sintered at $600-1000^{circ}C$ for 30 minutes in Ar atmosphere. We found that $MgB_2$ phase was mostly formed at the sintering temperature of $700^{circ}C$ and above, and the critical temperature ($T_c$) increased with increasing sintering temperature. For the $MgB_2$ sintered at $850^{circ}C$, the highest critical current density ($J_c$) was obtained to be $3.7{ imes}10^5;A/cm^2$ at 5 K and 1.6 T by a magnetic properties measurement system (MPMS). The addition of SiC to the $MgB_2$ wires changed microstructure and critical properties. SEM observation showed that the $MgB_2$ core had considerable micro-cracks in undoped wire and the density of micro-cracks decreased with increasing SiC contents. The critical temperature decreased as the SiC contents increased, on the other hand, the critical current density of SiC doped $MgB_2$ wires in high magnetic field was enhanced compared to that of undoped $MgB_2$ wires.