The structure and physical-mechanical properties of films of interpolymeric complexes (IPCs) based on sodium carboxymethylcellulose (Na-CMC) with urea-formaldehyde oligomers (UFOs) of different structure are studied in this article. It is shown that films of IPC have higher rate of deformative-strength properties and elasticity, minimal rate of solutions' viscosity with equimolar proportion of components of Na-CMC and UFO. The excess of Na-CMC or UFO causes the decrease of strength and elasticity which in turn is connected with decreasing of intermolecular links frequency. The decreasing of IPC elasticity with excess of Na-CMC or UFO is connected with creation of heterogenic structures, which can be seen in electronic microscope images. As a result, there were obtained films of IPC with various concentrations of triazinon cycle, which have a globular structure with different values of diameters (from 200 to 500 e), mechanical strength (80-140 MPa), modulus of elasticity (from 3 x 10(3) to 3.8 x 10(3) MPa), and the viscosity of solutions with a value in the range from 0.16 to 0.20 Pa s. Changing the structure of the interacting components gives the possibility to control substantially structure and properties of IPC based on Na-CMC and UFO. Regulation of physical-mechanical properties of the IPC films provides numerous opportunities for their applications as soil conditioners in agriculture and as a base for semisolid medicinal forms in pharmacy. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1749-1757, 2011