and Applied Analysis 3 Lemma 6 (see [17]). Assume that |Ω| < ∞, 1 ≤ p, r ≤ ∞, f ∈ C(Ω×R), and |f(x, u)| ≤ c(1+|u|). Then for every

in this paper, we investigate the existence of infinitely many solutions for a bi-nonlocal equation with sign-changing weight functions. we use some natural constraints and the ljusternik-schnirelman critical point theory on c1-manifolds, to prove our main results.