At present, searches are being made to accelerate the designing of new drugs and at the same time to considerably reduce the associated expenses. The process of designing a new drug generally consists of 3 stages: (1) search for a new agent having the required pharmacological activity; (2) experimental studies and pharmacological and toxological tests; (3) an appropriate pharmacological committee's approval for clinical tests of the agent. Stage 1 is the most expensive and labour-consuming, as it requires a half the total expenditures. Its clinical version consists in the synthesis of numerous homologues of the well-known biologically active compounds and in long-term and costly trials. At the same time, an investigator has a definite range of concepts of the structure of a new drug as a new representative of the known group that he already knows. The application of computer-aided analysis and design enables these disadvantages to be overcome. The introduction of methods for predesigning computer-aided drug design has permitted drastic reduction of expenses and accelerated designing of new drugs, by decreasing the number of unsuccessful syntheses and trials.