Abstract: Data on the structure and recognition properties of the template-selective binding sites in molecularly imprinted polymer membranes are presented. Porous molecularly imprinted polymer membranes based on semi-interpenetrating polymer networks (semi-IPN) were synthesized using the method of molecular imprinting in a combination with the method of computational modeling. Methacrylic acid, itaconic acid, and acrylamide were identified as optimal functional monomers for a model template -- atrazine. Optimal ratios between atrazine and functional monomers as well as their binding energies were determined using the method of computational modeling and compared with the experimental data on the adsorbtion capability of porous molecularly imprinted polymer membranes. The factors influencing quality of the template-binding sites in MIP membranes (binding energy template-functional monomer and the number of functional groups taking part in the recognition of the template molecule) were revealed. The computational atrazine-selective membranes were capable of highly-selective and effective adsorbtion of atrazine from its 10-9 - 10-4 M aqueous solutions, and were characterized by high stability during prolonged storage. The apparent structure of the synthetic mimics of biological receptors to triazine herbicides was compared with the structure of their natural counterparts Template and target information:atrazine Author keywords:molecular imprinting, molecularly imprinted polymer membranes, triazine herbicides, computational modeling