In this letter we propose a set of conditions on the joint probabilities as a test of genuine multipartite nonlocality without inequality. Our test is failed by all non-signaling local models in which even nonlocal correlations among some observables (not all) are allowed as long as these correlations respect the non-signaling principle. A pass of our test by a state therefore indicates that this state cannot be simulated by any non-signaling local models, i.e., the state exhibits genuine multipartite nonlocality. It turns out that all entangled symmetric n-qubit (n ≥ 3) states pass our test and therefore are n-way nonlocal. Also we construct two Bell-type inequalities from our proposed test whose violations indicate genuine multipartite nonlocal correlations.Introduction.-Local measurements performed on composite quantum system can lead to correlations incompatible with local hidden variable theory [1]. This phenomenon is known as quantum nonlocality, which has been recognized as an essential resource for quantum information tasks [2], such as quantum key distribution [3], communication complexity [4], and randomness generation [5]. Quantum nonlocality can be revealed via several ingenious ways such as the violations of various Bell inequalities [1,6], GHZ paradoxes [7,8], a kind of all-versus-nothing tests, and Hardy's test of nonlocality without inequality [9,10], a kind of all-versus-something tests. Most of these tests are designed to rule out 'standard' local realistic models, i.e., in the case of multipartite system each observer cannot have nonlocal correlations with any other distant observers.However, similar to the case of quantum entanglement, quantum nonlocality displays a much richer and more complex structure for the multipartite case than the bipartite case. In the case of three or more observers it is possible to have a hybrid local/nonlocal model in which some observers may share some nonlocal correlations. Still there are quantum correlations that cannot be explained by these more general local models and therefore these states exhibit genuine multipartite or n-way nonlocality [11]. Genuine multipartite nonlocality, being the strongest form of multipartite nonlocality in which nonlocal correlations are established among all the parties of the system, naturally attracts much interest recently. The detection of genuine multipartite nonlocality also witnesses genuine multipartite entanglement in a device-independent way.Svetlichny [11] introduced the notion of genuine multipartite nonlocality for the first time and provided a Bell-type inequality to detect genuine tripartite nonlocality. Recently the result was generalized to arbitrary partite cases [12] and arbitrary dimensions [13]. However Svetlichny's notion of genuine nonlocality is so general that correlations capable of two-way signaling are allowed