We investigate a class of nonlinear biharmonic equations with <
em>p
em>-Laplacian
where
N≥1,
β∈R,
λ>0 is a parameter and
Δpu=div(|∇u|p−2∇u) with
p≥2. Unlike most other papers on this probl
em, we replace Laplacian with <
em>p
em>-Laplacian and allow <
em>β
em> to be negative. Under some suitable assumptions on
V(x) and
f(x,u), we obtain the existence and multiplicity of nontrivial solutions for <
em>λ
em> large enough. The proof is based on variational
methods as well as Gagliardo–Nirenberg inequality.