The coupling selectivity was greatly enhanced by adding Li to La_2O_3,compared with thesingle La_2O_3.The O_2~- species was found on the Li/La_2O_3 but not on the single La_2O_3.In low temperaturedesorption,ethane desorbed trom the Li/La_2O_3 but was not detected with the single La_2O_3.It isconsidered that the addition of Li gave rise to some basic sites which are favorable for the couplingreaction. The coupling selectivity was greatly enhanced by adding Li to La 2 O 3, compared with the single La 2 O 3. The O 2 ~ - species was found on the Li / La 2 O 3 but not on the single La 2 O 3. In low temperature desorption, ethane desorbed trom the Li / La 2 O 3 but was not detected with the single La_2O_3.It isconsidered that the addition of Li gave rise to some basic sites which are favorable for the coupling reaction.