In this paper, SiC whisker reinforced Si3N4 composite was used for studying crack healing behavior. Surface crack and straight-through crack were introduced on the tensile surface of specimens by Vickers hardness indenter based on the single edge pre-crack beam method. The cracked specimens were heat-treated at 1000 °C, 1100 °C, 1200 °C and 1300 °C for 1 hour in air. Bending strength was measured at room temperature by three point bending tests. It was investigated that the best heat treatment temperature of Si3N4/SiC whisker composite is 1200 °C -1300 °C. The relationship between bending strength and logarithm of crack area was linear and parabola in original and heat-treated specimens, respectively. Crack healing behavior was analyzed by oxidation filling model according to oxidation kinetics.