The core of the various discussions on ‘Korean alphabet’ conducted during the modern enlightenment period was that Korean alphabet should be used instead of Chinese character when entering a new era. In the process, the reasons generally presented to support the merits of Korean alphabet over Chinese character were that Korean alphabet is a phonetic symbol unlike Chinese character and that phonogram had been more advantageous for universalization of knowledge and achievement of national prosperity and military power as it was proved by Western alphabets. However, actually the Korean alphabet during that time was not read so easily and various proposals were made for solution of such problems. The focus was shifted from the issue of ‘what kind of alphabet’ to ‘how to use it’. The question raised from this was the ‘original form, principle, system, etc. of Korean alphabet’. This, too, was the reason why various references were quoted or referred to for ‘Korean Alphabet Theory’. This study aims to investigate the references referred to in the process of the development of Korean Alphabet Theory in modern enlightenment period and their influence on the discussions conducted during that time.