The study sheds light on key words and their distribution within English scientific and technical text in the area of civil engineering. In this context the concepts of reference and core-reference are examined. The analysis of key words is linked to register analysis. It requires the identification of the pervasive linguistic features peculiar to particular register and textual field. Research methodology combines both quantitative techniques distinguishing statistically significant words and contextual analytical methods. Study results can be used in summarizing text contents.