The purpose of this study was to qualitatively analyze the process of how young children construct the concept of sound while participating in the science activity dealing with sound based on constructivism. The children who participated in this study were 10 five-year-old children currently attending S Elementary School Affiliated Kindergarten in Jeju-do. The activity was implemented for 10 weeks from October 24, 2011 through December 30, 2011, 3-4 times a week for a total of 27 times. The activity took 20-30 minutes during the Kindergarten s elective period depending on the children s interests and response. The children were divided into two groups of four or five members and each group engaged in the activity 3-4 times a week for a total of 27 sessions. The data was gathered using triangulation (Merriam, 1994) for the validity and reliability of qualitative study. Transcription of recordings, photographs of activities, teachers records, individual interviews with children, and children s artwork was collected in various ways, and these resources were processed through organization, categorical analysis, data classification and analysis, and interpretation. The results of the study were as follows: The process of constructing the concept of sound was categorized into 「discovery of sound」, 「discrimination based on sound-transfer tools」, 「understanding of listening through the auditory organ」, 「understanding of the relationship between the media that delivers sound and vibration」, and 「new understanding of sound」.