This paper investigates the development of Lithuanian intra-industry trade. The purpose of the research is to estimate the changes of Lithuanian intra-industry trade development under existing conditions. Seeking to define the changes of Lithuanian intra-industry trade, the basic methods of intra-industry trade measurement, the changes of intra-industry trade development and the importance of intra-industry trade on the development of trade structure between Lithuania and the EU are analyzed in this article. For measurement the changes of intra-industry trade development in the paper two approaches are adopted. The Grubel-Lloyd index was used to calculate the intensity of intra-industry trade and thus to determine its relative importance compared to inter-industry trade. Secondly, the index of marginal intra-industry trade was used to examine changes in trade flows over time. Using these methods of measurement and standard international made classification (SITC) was established the importance of intra-industry trade in the development of trade structure between Lithuania and the EU. It was found that trading in food, drink, tobacco, raw materials, machines and means of transport, chemical products, and other manufactured goods dominate between Lithuania and the ELT. These calculation results show the main directions of nature and pattern of international trade development. This research could be useful for preparing and forecasting the possibilities of Lithuanian intra-industry trade development