I discuss the mechanism of the creation of Japanese-Chinese isomorphous neologisms in modern times. I predominantly centered on the word “keiken” (experience) but also examined other words, such as “kesseki” (calculus) and “kesshoo” (crystal). Many modern Chinese words with a shared use appeared in translated works in Rangaku (Dutch Studies) during the Edo period. Focusing on that fact, I used works such as the Fushi Keiken Ikun, Kaijoo Hoojutsu Zensho, and Seimi Kaisoo to investigate 13 Japanese-Chinese isomorphous words from the very end of the Edo period. These words include “sabetsu” (discrimination), “kinshin” (probation), “dooro” (route), “densen” (infection), and “bokki” (erect). Finally, this paper discusses the Japanese-Chinese isomorphous word “sankoo” (reference) to point out that it is used as a verb with the particles wo and to in the Rangaku literature, although Japanese only uses it as a noun while Chinese also uses it as a verb. There are several other words like this, such as “shuei” (guard), “kankaku” (interval), and “eiyoo” (nutrition).