This paper is concerned with the existence and concentration of ground state solutions for the following class of fractional Schrodinger system (-Delta)(1/2)u+(lambda a(x)+1)u=H-v(u,v)in R, u,v is an element of H-1/2(R), (-Delta)(1/2)v+(lambda a(x)+1)v=H-u(u,v)in R, u,v is an element of H-1/2(R), where H has exponential critical growth, lambda is a positive parameter and a(x) has a potential well with int(a(-1)(0)) consisting of k disjoint components Omega(1), ... Omega(k). The proof relies on variational methods and combines truncation arguments and the Moser iteration technique.