Abstract: Based on researches of Haiguotuzhi in the late Qing Dynasty, Cihai and the dictionary of mandarin in the Republic of China, and the new Cihai published in 2009, we put forwards the term changes of scientific nomenclature, and discuss name diachronic changes from the perspective of internal form of word formationform. We also discussed the definition of internal form and the relations with motivation, and suggested that five basic principles for nomenclature: fluctuating variability, exclusiveness, national characters, poly-sources, and textual. Our results can provide methods and basis for the nomenclature standardization, and make sense to perfect the nomination of scientific terms.

Key words: internal form, motivation, basic principles