All polymer gas-seinsing organic FETs with alcohol adsorptive polymeric gate have been fabricated. Polyhexylthiophene(PHS) as well as poly(ethylene-dioxythiophen)/polystylene sulfonate (PEDOT/PSS) has been used as semiconducting layer with polyvynylphenol (PVP) as gate dielectric polymer in this study. The panar type gas-sensing OFET presented clear FET characteristics with low voltage operation (less than 5V) under exposing alcohol vapor, which represents the device are sensitive to alcohol. A gas-sensing filter with through hole filter as base material with PEDOT/PSS and PVP was also fabricated. The device successfully represented the change in the drain current by injecting alcohol mixed air.