In this article, we study the effective elastic and plastic properties of particle-reinforced composite mterials with imperfect interface. The imperfect interface is described by a spring-type model assuming that the traction conitnuity remains intact, while the displacement experiences a jump proportional to the interfactial traction. Both the tangential and normal displacement discontinuities at the interfaces are considered and the effective elastic moduli are obtained using a generalized version of dilute model, self-consitent model, Mori-Tanaka model, and efferential model. A comparison between the effective elastic moduli obtained by these different models is made and the determination of an effective plastic behavior of particulate composite materials, by means of the Mori-Tanaka model and secant moduli method, is also discussed. Finally, we examine the influence of interfacial compliance on the macrossopic averaged mechanical properties of composite materials.