Abstract-Lexical gap in translation is deeply debated during the history of translation studies. Many theories have been put forward to explain the possible strategies of filling lexical gaps. This descriptive study aims to investigate some of these strategies used in the translation of a special technical book, Biomass Gasification & Pyrolysis (Practical Design and Theory), this book was a suitable option, since it has modern topics, some of which have not been discussed or even existed in the target language (Persian). In this study, seventy new terms which have not been employed in Persian (in that field) were selected and examined, the qualitative and quantitative analysis of the words indicated that loan word, loan translation, loanblend were the most prominent strategies to cope with new lexicons; in addition, it also showed that loan translation had the highest rate of usage (68.5%) among other techniques and in scientific contexts it is widely preferred.