The composite materials, 3Y-TZP added with TiN or/and Al2O3 particles, were fabricated by hot-pressing techniques. The effect of TiN and Al2O3 on the low temperature degradation of 3Y-TZP was investigated. It is shown that both TiN and Al2O3 can inhibit t-m transformation of 3Y-TZP and prevent the transformation from propagating into the specimen interiors when aged at a low temperature. The inhibition to the low temperature degradation of 3Y-TZP by Al2O3 is more sensitive to the aged temperature than by TiN. Compared with Al2O3, TiN is more available to inhibit t-m transformation on aged surfaces. The degradation resistance of 3Y-TZP codoped by TiN and Al2O3 is stronger than that of 3Y-TZP dispersed only by TiN or Al2O3.