An experimental study on the improvement of aerodynamic characteristics of wing-body configuration RLVs (Reusable Launch Vehicles) due to lateral blowing has been conducted. Two fuselage-cross sections have been considered: a square and a triangular cross section with rounded corners. The models have single-delta wings of modified NACA0010 with 45° sweepback angle. Lateral blowing is realized by injecting a pair of sonic jets parallel to the trailing edge of the wing. Experiments have been conducted in the wind tunnel of ISAS (Institute of Space and Astronautical Science), JAXA (Japan Aerospace Exploration Agency) under a test condition of free-stream Mach number M ∞=0.29, Reynolds number Re=3.1×106, angle of attack α=0° ∼40° and jet momentum coefficient C μ=0.015. Results show that lateral blowing increases lift of the models over a wide range of angle of attack. Especially a significant increase in lift is achieved in the case of a "square" model at high angle of attack, as compared to a "triangular" model. Using the experimental results, we evaluate the effects of the fuselage-cross section for RLVs on aerodynamic characteristics from lateral blowing. And we confirmed that lateral blowing is useful for lift augmentation of RLVs in subsonic flow.