In this paper, we consider the following fractional Schrödinger equation ε 2 s ( − ∆ ) s u + V ( x ) u = P ( x ) f ( u ) + Q ( x ) | u | 2 s ∗ − 2 u in R N , where ε>0 is a parameter, s∈(0 ,1), 2 s ∗ = 2 N N − 2 s , N>2 s, ( − ∆ ) s is the fractional Lapalacian and f is a superlinear and subcritical nonlinearity. Under a local condition imposed on the potential function, combining the penalization method and the concentration-compactness principle, we prove the existence of a positive solution for the above equations.