This study attempts to identify how much Korean arguments are pro-dropped or overtly occur in narratives1 by introducing referential density values in Korean. Referential density studies in linguistics have recently started by Bickel (2003) and Noonan (2003a, 2003b). The referential density values of a language mean the ratio of how many NP arguments overtly occur in the smallest unit for the discourse analysis (Bickel 2003, Stoll and Bickel 2009; Noonan 2003a, 2003b). The present study pays attention to referential density in Korean with the narratives of the ‘Frog Story’. First, the handbook of referential density values (Noonan 2003b) is introduced; second, it is presented how the guidelines of the handbook can be applied to the structure of the Korean narratives; third, the results of calculating the referential density values in Korean follow the Korean narrative structure; and finally, it is discussed what the results indicate and what this research can contribute to the future studies.