Abstract: A wind tunnel test program is designed to investigate aerodynamic characteristics of different grid fins in subsonic and transonic flows, which has advantages of simple model design, avoiding installation of hinge moment balance on small models, and obtaining all aerodynamic forces and moments of grid fins. The aerodynamic characteristics of grid fins are analyzed, including simple frame configuration, upright honeycomb configuration and skew honeycomb configuration with different grid densities. The aerodynamic characteristics of different grid fins and planar fins are compared, and the influence of grid fin location on its aerodynamic characteristics is also investigated. The results show that grid fins and planar fins have respective advantages and disadvantages; the configuration, grid densities, and size of grid fins have an important impact on their aerodynamic characteristics. For different grid fins, the influence of location on its aerodynamic characteristics is not the same.