Abstract: Iwan model, which is commonly applied to describe the properties of energy dissipation and damping occurred in joints, becomes a meaningful tool for understanding both static and dynamic nonlinearity mechanisms of jointed structures. This paper presents a six-parameter Iwan model based on the non-uniform density function which contains an abridged power-law distribution and two impulsive functions. The analytic expressions of the six-parameter Iwan model including the backbone curve, unloading curves and energy dissipations during both micro-slipping and macro-slipping are deduced. Discussions on the effects of model parameters to energy dissipation are also performed. Compared to those existing Iwan models, the presented one is able to give a better description on the experimental phenomena of jointed structures.