Highly ethylene-selective organic inorganic hybrid membranes were prepared via sol gel method and Ag+-exchange treatment. The ratio of the permeance, C2H4/C2H6 through the membrane was more than 90 at 373 K and showed a dependence on temperature. Increase in the measurement temperature promoted the decomplexation of C2H4 from sites. The membrane indicates C2H4 selectivity even at relatively high temperature and at 298 K using a mixture of 50% C2H4-50% C2H6 as feed gas.