Composition modulation strategies for improving selectivity to the C-2 products in the oxidative coupling of methane were investigated experimentally with Li2O/MgO and CeO/Li2O/MgO catalysts at about 100 kPa pressure and 750 degrees C. Strategies used were 1) "methane cycling" between mixtures with different concentrations of CH4, 2) "oxygen cycling" between mixtures with different concentrations of oxygen, 3) bang-bang cycling (air-CH4), and 4) flushing the catalyst with an inert between exposures to reactants. Experimental C-2 yields and ethylene to total C-2 ratios showed that composition forcing is better with the Ce/Li/MgO catalyst. Methane cycling proved to be the best strategy explored.