This study is the survey on the usage and the effect of 39 words of Japanese style Western words remaining in Korean language, targeting Korean people in their 30s and 40s. As a result, It can be seen that 50percent of 30s use 24 Japanese style Western words, and 50percent of 40s use 26 Japanese style Western words. And most people in their 30s and 40s recognize these words as Japanese and even use them without hesitance. However, there are a few words that are rarely used. On the other hands, As a result of confirming whether usage of the words is related to the recognition of Japanese style words, it was found that the recognition of Japanese style words did not significantly affect the usage rate. And It was confirmed that the influence of the hesitance of the words itself and the effort to purify the Korean language have a greater effect on the usage of the words. However, despite the effort to purify the Korean language, some Japanese style words are still in use. Regarding this phenomenon, we predict the future direction of language change depending on whether if there are substitute words for Japanese style words or not, and propose a way of accepting Japanese style words that are already familiarly used in our lives.