Lexical competence formation is an essential part of teaching communication within ESP course. Nowadays due to globalization processes in education it is vital not only to know glossary of specialist terms but also be able to use it. This article is concerned with the main approaches to learning glossary via various Internet-resources and difficulties which students might face during vocabulary learning. Using Internet-resources, such as online dictionaries, corresponds to the modern tendency of exploiting Internt-based educational materials and can serve as an effective base for enhancement and usage of general and professional vocabulary. Thus, it stimulates lexical competence formation in students from technical departments.