Organic amine solution is currently the most commonly used chemical absorbent for carbon dioxide (CO2) capture, but its drawback such as high energy consumption for regeneration of CO2 loaded solution has seriously hindered its wide application in industry. Development of catalysts could reduce the regeneration energy consumption of the process. In this study, the catalytic effects of raw multi-walled carbon nanotubes (MWCNTs) and acid-treated MWCNTs in 30 wt% monoethanolamine solution on both absorption and desorption procedures were investigated. The results showed that the addition of raw MWCNTs and acid-treated MWCNTs as catalysts both promoted the CO2 desorption rate and amount, among which the 700 ppm acid-treated MWCNTs increased the CO2 desorption amount by 48.49 %. Furthermore, both MWCNTs shortened the desorption time of CO2 as well. Stability of acid-treated MWCNTs has been examined by 20 cycles in the capture system. Characterization results indicate that the acid treatment increased the surface area of MWCNTs, and created more acid sites on their surfaces through the defected area. Both characteristics contribute to the enhanced CO2 desorption performance. Therefore, acid-treated MWCNTs can be considered as promising catalysts for promoting CO2 desorption and reducing energy consumption for CO2 capture.