In this paper, we consider the following Schrödinger‐Poisson system:
−normalΔu+λϕfalse|ufalse|2α∗−2u=()∫R3false|ufalse|2β∗false|x−yfalse|3−βnormaldyfalse|ufalse|2β∗−2u,in5ptR3,false(−normalΔfalse)α2ϕ=Aα−1false|ufalse|2α∗,in5ptR3,
where parameters α,β∈(0,3),λ>0,
Aα=normalΓfalse(3−α2false)2απ32normalΓfalse(α2false),
2α∗=3+α, and
2β∗=3+β are the Hardy‐Littlewood‐Sobolev critical exponents. For α<β and λ>0, we prove the existence of nonnegative groundstate solution to above system. Moreover, applying Moser iteration scheme and Kelvin transformation, we show the behavior of nonnegative groundstate solution at infinity. For β<α and λ>0 small, we apply a perturbation method to study the existence of nonnegative solution. For β<α and λ is a particular value, we show the existence of infinitely many solutions to above system.