Traditional Japanese linguistics classifies the lexical strata into four types: Yamato words, Sino-Japanese words, foreign words, and hybrid words. The focus of this classification is on the word level, based on the origins of the words. However, recently some scholars have advocated a new classification of Yamato words, Sino-Japanese words, foreign words, and mimetic words, which focuses on the morpheme level and the morphophonological characteristics of morphemes. This paper argues that both classifications have their own applications. The traditional classification is suitable for diachronic studies of lexical evolution, while the new classification is suitable for synchronic studies of phonology and word formation. The Chinese translations of the terminologies related to the Japanese lexical strata are somewhat confusing. By referring to the usage of related terms in the research on other languages, this paper analyzes current Chinese translations of kango (Sino-Japanese words), gairaigo (loanwords from languages other than Chinese) and wago (Japanese native words), and proposes alternative Chinese translations. Furthermore, translation strategy for Japanese linguistic terminologies is also discussed.