In this paper we study the concentration phenomenon of solutions for the nonlinear fractional Schrödinger equationε2s(−Δ)su+V(x)u=K(x)|u|p−1u,x∈RN, where ε is a positive parameter, s∈(0,1), N≥2 and 1<p<N+2sN−2s, V(x) and K(x) are positive smooth functions. Let Γ(x)=[V(x)]p+1p−1−N2s[K(x)]−2p−1. Under certain assumptions on V(x) and K(x), we show existence and multiplicity of solutions which concentrate near some critical points of Γ(x) by a perturbative variational method.