Abstract: A method of producing water-soluble urea-formaldehyde resins modified with aliphatic polyamines, residing in that 1 mole of urea, 1.5-3.0 moles of formaldehyde, and branched aliphatic polyamines with molecular weight 200-440, containing 10-16 wt.% of tertiary nitrogen, are reacted at 80-100.degree. C and pH of an alkaline medium 7.2-9.5 attained by the proper amount of polyamines. Aromatic or aliphatic sulphonic acids of the general formula R-SO.sub.3 H, where R is aryl or alkyl, are introduced into the obtained mixture until pH of an acid medium 4.8-6.0 is attained. Then an alkaline agent is added up to pH 7.2-9.5. As a result an oligomer is formed which is reacted with polyoxyethylene ether or isooctylphenol with 7-11 oxyethylene units at 100-105.degree. C. The ethers are taken in amount of 0.2-2.0 wt. parts per 100 wt. parts of the initial urea.