Recently, not only the demand for air-conditioner is increased, but also air-conditioner becoming most favor home appliances in the present. But air-conditioner generate a great deal of noise among home appli-ances, become a target of public grievance. Especially, air-conditioner outdoor room system occur vibration, and it cause second noise that transfer to another part. Therefore, to reduce the air-conditioner outdoor room system vibration become a big issue of today. In this study, using conventional transfer path analysis, esti-mate operational forces of compressor of air-conditioner outdoor system which was main vibration source. However, conventional transfer path analysis method is not considered global mode that air-conditioner out-door whole system movement. Therefore, to correct the flaw of conventional transfer path analysis, modified transfer path analysis is proposed in the paper. Apply to simple hinged-free model which has global mode, validate the modified transfer path analysis through comparison both results, conventional and modified transfer path analysis. Also modified transfer path analysis apply to real air-conditioner model, obtain opera-tional forces without influence of global mode and resonant frequency.