New method for preparation of organic aerogels by sol-gel polymerization of formaldehyde with polyphenols (PFs), isolated from larch bark of and inner birch bark, was developed. The functional composition and properties of the original PFs were studied by thermogravimetry methods and FTIR- spectroscopy. It was found that larch polyphenol substances possess greater thermal stability in the temperature range 25-700 °C, while the process of thermal decomposition of birch bark polyphenols completes to 600 °C. It has been established that polyphenol larch compounds in their composition contain more aromatic structures and hydroxyl groups. The effect of the pH value of gelation solutions in the range of values from 4 to 12 on the porous structure of organic gels synthesized on the basis of polyphenols was studied. Porous structures and adsorption properties of polyphenol-formaldehyde organic gels were studied using BET method, scanning electron microscopy and sorption (methylene blue and gelatin). It is shown that an increase in pH contributes to the formation of a product with a more compacted texture. The electron microscopic images of polymer gels demonstrate a uniform granular texture with visible micro globules with an average particle size of ≈ 50-70 nm.