Crack distribution, mechanical performance recovery of selfhealing engineered cementitious composites(ECC) materials under wet/dry conditioning cycles and nanoidentation analyses of the microphases in ECC at 0.3%, 0.5%, 1.0% and 2.0% preloading were investigated. The results suggest that ECC has many characteristics that contribute to selfhealing behavior. Majority of ECC cracks are below 30 μm in width. Both ultimate tensile strength and tensile strain capacity of the majority specimens at reloading are higher than the control specimens. The modulus of elasticity, hardness and stiffness of healed products is about 34.8 GPa, 1.6 GPa and 0.1 mN/nm respectively.