There are three ways to spell gayagum in Chinese, that is, 加耶琴, 伽耶琴, and 伽倻琴. These are used together today. In the world of music academy, 伽倻琴 is preferred. However, this is even different from the name of the country, 加耶, in the same dictionary. Why has there been so many different Chinese letters for this musical instrument? The purpose of this study is to look for the right Chinese spelling of gayagum in the music academic world with the three questions in mind; what the oldest historic record is and how gayagum was spelled in the book, when the three Chinese names of gayagum were starting to be used together and why the name of the country, Gaya is spelled especially as 加耶 in Chinese letters. As the result of the discussion above, I suggested that 加耶琴 would be the most appropriate Chinese letters. Following reasons could be brought up for this choice. First, it is recorded as 加耶琴 in the oldest historic record, Samguksagi 『三國史記』(History of Three Kingdoms). Second, the descendant scholars changed 加耶琴 into 伽耶琴 and 伽倻琴 in their books when they quoted the preceding documents. Therefore, as long as the plausible reason is not discovered for changing 加 into 伽, and 耶 into 倻, I think 加耶琴 is the right chinese letters. Finally, since gayagum was first invented in the ancient country, Gaya and it began to be called gayagum when it was introduced to Shilla it`s easy to guess that the instrument was named after the country that it came from. In other words, since it was a stringed instrument(琴) of 加耶, it will be appropriate to be spelled 加耶琴.