Al-doped Ti3SiC2 ceramics were prepared by hot-pressing sintering, which were characterized and measured for oxidation resistance and microwave dielectric property by X-ray diffractometer, scanning electron microscope, energy dispersive spectroscopy and vector network analyzer, respectively. Results showed that the prepared ceramic with Al doping had higher mass fraction of Ti3SiC2, and that the as-prepared ceramic grains had the typical laminated appearance. Through the Al doping approach, the oxidation resistance of Ti3SiC2 ceramic at 1200℃ was efficiently improved, and its real component ε′ and imaginary component ε″ of permittivity were greatly increased, compared to undoped sample, which were 60.8 and 6.28 in average in the frequency range of 8.2-12.4GHz, respectively.