Term variation is an inevitable phenomenon in scientific and technical translation.This paper explains the definition of term variation,and analyzes the traps of term variation in five aspects,i.e.,the same term in different domains,stylistic differences,avoidance of repetition,geographical naming in different cultures and social-cognitive development.Furthermore,the paper proposes some countermeasures in order to translate the terms appropriately:establishing subject terminology database,choosing flexibly term variation for various texts,and verifying the terms by search engines.