Molecular dynamics calculations were made of the distance from the hydrogen atom of the imino group to the distance of the oxygen atom of the carbonyl group of poly(imino imino ketone ketone) (PIIKK). The results showed that theoretically there was hydrogen bond formation between the hydroxyl group and the carbonyl group of PIIKK. The existence of the hydrogen bonding between the polymer chains of PIIKK was confirmed by infrared spectrum analysis. Due to the existence of the hydrogen bonding, the glass transition temperature increased to 273?C from 143?C for poly(ether ether ketone) (PEEK).