The results of studies of humic acids electronic spectra for various types and kinds of peat in the middle-taiga zone of Western Siberia (Khanty-Man-siysk Autonomous Circle - Yugra) are presented in the study. It was found out that the increase in opti-cal density was observed in the samples of humic acids which were extracted from the peat with a high degree of decomposition (40-65 %). At the first approximation the interpretation of received electronic spectra gives reason to range humic ac-ids in the order with increasing proportion of aro-matic structures share in macromolecules in the following order: 1) peat humic acids having a de-gree of expansion from 0 to 35 % with the content of a large number of peat-forming plants, where the extinction coefficients vary from 0.039 to 0.054 or sphagnum peat with the same degree of decompo-sition with the sphagnum containing 95-100 %, where the extinction coefficients have values be-tween 0.030 and 0.042; 2) humic acids of all types and kinds of peat with a degree up to 35 %, where the extinction coefficients are from 0.042 to 0.068; 3) humic acids of peats of all examined types and species with a degree of decomposition from 40 % to 65 %, where the extinction coefficients vary from 0.059 to 0.087. Although the method of electron spectroscopy is an important tool in the study of humification processes in peat, it has a limited in-formative value due to unresolved spectra. Thus, peat humic acids with various botanical composi-tions and various degree of decomposition are cha-racterized by similar absorption spectra in the visi-ble area in the form of a monotone increasing of absorption in short wavelength interval and differ from each other only by the absorption intensity.