The purpose of this study was to examine the development and characteristics of invented notation for musical representation. A total of 168 young children aged 3, 4 and 5 years participated in this study. The children listened to rhythm and melody, which represented music, to reveal their use of invented notation. The Korean children used various types of invented notation involving figures, numbers, "Hangeul" (Korean letters), lines, and mixed forms. The level of invented notation increased with age, similar to other kinds of representation competence. The level of invented notation was clearly and significantly higher when paper and drawing tools were used than when blocks were used. However, there was no significant difference in invented notation according to the type of music played (voice or instrument). This study suggests that providing children with various examples of musical experiences and representations as well as tools allows them to perform free and immediate representation without requiring dual representation. Additionally, the findings confirmed that Hangeul has an advantage in children's musical representation.