Zr(Ca)-Al-O-N composites were prepared with ZrO2(Ca) (i.e Ca-PSZ, d50 < 10 μm) and Al powder (d50 =7.5 μm, 29 μm, and 62 μm) as raw materials by in situ reaction sintering in N2 atmosphere at 1600 °C. Phase constiturion of the composites was affirmed by XRD and SEM-EDS, and effect of grain size and content of Al powder on sintering performance of the composites was investigated, and oxidation characteristic of the composites were analysed by measure increasing weight of oxidation. The results showed that major phases of the composites composed of (t+c)-ZrO2, ZrN, ZrAl3O3N and CaAl12O19, and Al powder of 5 wt% - 7 wt% d50 =7.5 μm and 3 wt% - 5 wt% d50 =29 μm were suitable for preparation of the composites and bendiing strength of its samples sintered at 1600 °C had 60-90MPa. In atmosphere, oxidation onset temperature of Zr(Ca)-Al-O-N composites were approximately 550 °C, and the end temperature of its oxidening were approximately 950 °C. Treating with antioxidation is a key for application of Zr(Ca)-Al-O-N composites.