The book is devoted to data structures, which are the basis for such sections of computer technology as storage and sampling of information, operating systems, compiler development, machine graphics, artificial intelligence, etc. Primitive data structures and operations on them, processing of character strings, issues of formal grammars, linear data structures (arrays, stacks, queues, lists), non-linear structures (tree structures), sorting and search methods, file structures and operations on them are considered. Most concepts are illustrated by algorithms and programs written in PL1.