This research is to study on the distinction of two type medials -mainly on rhyme compound vowel finals- in sino-korean which is comparative study with sino-japanese Go’on & Kan’on. The results of this research are as follows. 1) Two type medials appeared same form in sino-japanese Kan’on that reflected rate middle chinese except Yu(虞) rhyme. 2) Two type medials appeared different form in sino-japanese Go’on that reflected early middle chinese except Xiao(宵) rhyme & group Zhi(止). I thihk Xiao(宵) rhyme was reflects of front vowel-a because of compound non-medial Xiao (肴) rhyme appeared ?eu form. Case of group Zhi(止), I thihk that appeared same form because of Japanese have no distinction of i & ii. 3) Two type medials appeared different form in sino-korean except Xiao(宵) rhyme. I thihk Xiao(宵) rhyme was reflects of front vowel-a because of compound non-medial Xiao(肴) rhyme appeared ?jo form as like sino-japanese Go’on. Only 3 letters of 249 letters appeared same form and another appeared different form in sino-korean. It means sino-korean was originated in early middle chinese as like sinojapanese Go’on.