  An experimental setup for testing quantum nonlocality of N qubits is
proposed. This method is a generalization of the optical setup proposed by
Banaszek and Wodkiewicz [1]. The quantum nonlocality of N qubits can be
obtained through its violation of N-qubit Bell inequalities. The correlation
function measured in the experiment is described by the Wigner function. The
effect of inefficient detector is also considered.
