According to patent legislation depositing is a means of protecting micro-organisms as objects of invention. Establishment of the state system for deposition of micro-organism strains was specified by the 1993 Ukrainian law "On protection of rights for inventions and useful models", and came into force through decision 12.10.94 N 705 of the Ukrainian Cabinet. The system of official Ukrainian depositories is now up and running. Special departments for deposition of biotechnological strains were organized in particular institutions: for non-pathogenic micro-organisms, the D.K. Zabolotny Institute of Microbiology and Virology (National Academy of Sciences of Ukraine); for pathogenic micro-organisms, the Kiev Institute of Epidemology and Infectious Diseases (Ministry of Health) and the Kiev branch of the Institute of Veterinary Medicines and Fodder (Ministry of Agriculture). Legislation regulates the functioning of depositories, and the procedure for deposition, in particular, reception and registration of micro-organisms, confirmation of their authenticity, maintenance and long-term storing, strains delivery and information support. Strain deposition guarantees storage of micro-organisms for not less than 30 years. The deposited strain is of particular value in cases where an author's rights may have been violated or there is argument about novelty. An author can control usage of their organism before patenting and, after taking out a patent, can get current information about its delivery. Deposition guarantees conservation and accessibility of the strain for public use. The formation of the national system for deposition of micro-organism strains is still in progress. Deposition of other biological objects, which are not micro-organisms, but which need a similar mode of preservation and storing, is a question awaiting a solution.