The aerodynamic properties of a canard-configuration WISES (Wing In Surface Effect Ship) flying over calm water and/or waves are studied from experimental and theoretical points of view. A canard-configuration WISES without PAR (Power Augmented Ram) was originally proposed by Kubo and Akimotol¹⁾ and it enables easy detachment from the waves utilizing the large trim angle of the ship induced by the front wing. On the other hand, it has been suspected for the WISES that the stability is one of the serious problems against the disturbance due to the gust or waves. However the aerodynamic properties of WISES for such disturbance have not been yet made clear in detail. In this paper, the model experiment is carried out in a towing tank imitating the WISES flying over calm water or waves, and the aerodynamic properties as well as the aerodynamic interaction effect of wings are investigated. Theoretical computations based on the BEM are also carried out and the results are compared with experiments. Through the study it is confirmed that the effect of the disturbance due to waves on the stability of WISES is scarcely to be considered, and also that the proposed theoretical method can predict aerodynamic properties of WISES in good accuracy.