Hydrogen bonding interaction in the blends of polyamide 612 (PA(612))/ethylene vinyl alcohol copolymer (EVOH) and the effect of the hydrogen bonds on the characterization of PA(612)/EVOH were investigated. Fourier transform infrared spectra (FTIR) analysis indicated that the interactions between the carbonyl groups of PA(612) and hydroxyl groups of EVOH increase as the content of EVOH in PA(612)/EVOH specimens increase. This interaction between PA(612) and EVOH leads to their miscibility to some extent in the amorphous region and even some effects on their crystal phase, respectively. Further isothermal crystallization behavior of PA(612)/EVOH indicates that the hydrogen bonding between PA(612) and EVOH leading difficulty in crystallization of PA(612). Several kinetics equations are employed to describe the effects of EVOH on the crystallization properties of PA(612) in PA(612)/EVOH blends in detail. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120:3724-3732, 2011