In this paper, we study the following nonlinear Schrödinger-Poisson type equationwhere ε > 0 is a small parameter, V : R 3 → R is a continuous potential and K : R 3 → R is used to describe the electron charge. Under suitable assumptions on V (x), K(x) and f , we prove existence and concentration properties of ground state solutions for ε > 0 small. Moreover, we summarize some open problems for the Schrödinger-Poisson system.