Abstract: The capacities of removing oxygen in ethylene with MnO/CaAl2O4 and MnO-Ag/CaAl2O4 scavengers at different reduction temperatures were compared. The effects of reaction temperature，pressures，ethylene space velocity，and oxygen concentration in ethylene on the oxygen scavenger capacity and residual oxygen in ethylene of MnO-Ag/CaAl2O4 scavenger were investigated. The reduction temperature for regeneration of MnO-Ag/CaAl2O4 was 180℃ lower than that of MnO/CaAl2O4. Under the testing conditions：reaction temperature 25—150 ℃，ethylene pressure 0.50—3.0 MPa，space velocity 1200—8000 h－1，oxygen in ethylene could be removed from 50—1000 μL/L to below 0.050 μL/L by MnO-Ag/CaAl2O4. The oxygen removing capacities of MnO-Ag/CaAl2O4 were more than 7.0 mL/g and 11.0 mL/g at temperature 25 ℃ and 80 ℃，respectively. MnO-Ag/CaAl2O4 could be regenerated many times and would not lead to polymerization，oxidation and other by-products of ethylene.