Nacelle-wing/body interference phenomenon is one of major engineering subject for future SST (Supersonic Transport) aerodynamic design. The wind tunnel test has been performed at FHI (Fuji Heavy Industries, Inc.) high speed wind tunnel using SST half model which can set the various nacelle configurations (nacelle up/down, in/out, forward and nacelle off). This paper describes the wind tunnel test result about the effect of the nacelle installation position.