Self-crack-healing behavior under a combustion gas atmosphere with a low oxygen partial pressure, P-O2, is important for actualizing ceramic gas turbines, but to date only self-crack-healing behavior in air has been investigated. In this study, we investigated crack-healing behaviors at 1273-1773 K under several levels of P-O2. Crack-healing in atmospheres with P-O2 >= 50.0 Pa gave rise to the complete strength recovery of cracked specimens, resulting from passive oxidation. Based on the obtained results, the kinetics for strength recovery by self-crack-healing was expressed as a function of healing temperature, TH (K), and P-O2 (Pa). The strength recovery rate for complete crack-healing, H-nu (s(-1)), could be expressed as H-nu=6.95 x 10(5)exp(-4.65 x 10(4)/T-H)P-O2(0.835) Using this rate equation, one can evaluate the healing time for complete strength recovery under combustion gas in a gas turbine.