A concept of equivalent inhomogeneity is adopted to facilitate analysis of effective properties of particulate composites with surface-varying interphases. The basic idea is to replace the inhomogeneity and its interphase by a single equivalent inhomogeneity, combining properties of both. It is illustrated considering spherical inhomogeneity with spring layer model of interphases. Due to surface-varying properties of the interphase the resulting equivalent inhomogeneity is anisotropic. Thus, the Method of Conditional Moment – developed for composites with anisotropic constituents – is applied in analysis of the effective properties of the composite. For particular case of homogeneous interphase, the results obtained here are compared with those available in the literature.