The present disclosure relates to a cucurbituril-polyethylenimine-silica complex, a method for preparing the same and a carbon dioxide absorbent containing the same. According to the present disclosure, a cucurbituril-polyethylenimine-silica complex may be prepared by forming a complex wherein a cucurbituril is bound to polyethylenimine and including the same inside silica, and it may be used as a carbon dioxide absorbent with superior thermal stability and prevented formation of urea.