Interface properties are critical in determining the tough mechanical behavior of ceramic matrix composites (CMCs). This chapter investigates the relationship between the macroscopic mechanical behavior of composites and their interface properties in CMCs. Typical macroscopic mechanical parameters, such as first matrix cracking stress (FMCS), matrix cracking saturation stress (MCSS), crack opening displacement (COD), and hysteresis-based damage parameters, were derived from mechanical experiments. Micromechanical models for predicting FMCS, MCSS, COD, and cyclic hysteresis loops were established and utilized to analyze the mechanical behaviors associated with these phenomena. Additionally, the effects of interface properties on the composite’s mechanical parameters were also examined.