Based on the early study of Emanuel and Nolan's (2004) original genesis potential index (GPI) and the Emanuel's (2010) revised version (χGPI), in which the relative humidity term was replaced by moist entropy deficit, we proposed a new typhoon genesis potential index (χMqGPI) designed specifically for the western North Pacific basin. We utilized the NOAA's best-track typhoon data and ECMWF's atmospheric reanalysis data to demonstrate the advantage of χMqGPI over the western North Pacific in comparison with GPI and χGPI.