This article describes the structure detection module of recognition of the structure of assembly technical documentation of railway automation and remote control devices (MTD). This module is offered as an addon and an improvement of the specialized software complex for MTD recognition. The module operation can be roughly divided into fi ve stages of recognition. The fi rst stage is the determination of the type of the document to recognize. The second step is the recognition of the basic elements of the document, which are used in the following algorithms. Depending on the type of the document to recognize different algorithms are used in subsequent steps. The next step is sorting of obtained compo-nents, and also fi nding patterns in the document, that is necessary for detection of structure elements, non-recognized at the previous stage. Next, obtained data are compared with known templates of assembly documentation. If the document does not correspond to a certain type of assembly documentation, the found patterns are used. At the last stage there is search for missing components of the assembly diagram, if any. The article describes in detail algorithms of recognition of tabu-lar structures of documents, in particular the algorithm of basic elements search and the algorithm of missing elements search. It also gives a comparison of the effi ciency of described module with the existing most technological counterpart. The article provides test results for the module for different types of assembly documents.