The experimental study on the mechanism of CO 2 absorption and desorption was tested by two kinds of glycinate (SG and PG) with TEA. The absorption and regeneration of CO 2 by mixed absorption liquid were tested and compared with each other. The results showed that a low concentration of TEA in the SG and PG increased CO 2 absorption capacity of mixed absorption solution. Addin more TEA on PG or SG lowered CO 2 absorption capacity of mixed absorption solution. Desorption of PG didnt change with TEA. The low concentration of TEA had a role in promoting the desorption of mixed absorption solution (SG+TEA), and the high concentration of TEA inhibited the desorption of mixed absorption solution (SG+TEA).