An Shigao of the Parthian Empire arrived at Luoyang in the Late Han Dynasty, and initiated translation of Buddhist texts into Chinese. Because he was a first translator, he experienced various difficulties with respect to selection of appropriate vocabulary and idiom. The chief difficulty was to determine proper word choice and usage essentially by himself. This paper addressed the question of why no later translators shared An Shigao's equivalent for gatha, jue _??_ and why the translator Jiumoluoshi (_??__??__??__??_) changed jue _??_ into ji _??_. Further, I explore why Shenajueduo (_??__??__??__??_) in the Sui dynasty changed ji _??_ into qieta _??__??_.