The method of IR spectroscopy was used to study extracts of p-ni troplienol (NP) with neat butyl acetate (BA). It was found that hydrated H-complexes NP'H2O't (BA)2were preferably formed. In those complexes, the molecule of NP is H-bonded with the oxygen in H20, while both protons of H20 are H-bonded with the BA molecules. With growing C, polymers (NP H2O BA) 'BA containing bridged molecules of BA are formed. The C=0-groups in BA are H-bonded with two water molecules. The NP extracts with 1.5 M BA solutions in CCl24contain mostly H-coraplexes as NP'BA associated with another BA molecule by outer-spheric interactions. Also, hydrates NP’(H20) BA with 1=1,2 are found at high NP concentration, whereas NP'H20’(BA)2is formed at low NP concentration. Our discussion is concerned with the existing interconnection between the structure and composition of associftes formed in the extracts and the strengths of H-bond in these associates, judged by the values of low-frequency shifts υOH) of H20 and NP and υC=0) of BA in their IR spectra.