Background and Objectives : The current study aimed to 1) compare of Lingual function and alveolar sounds between 4-year-old Korean children with and without ankyloglossia, 2) investigate the correlation between ① maximum lingual length-protrusion(MLL-P) and percentage of consonants corrects(PCC) focused on alveolar sounds, ② lingual movement and PCC focused on alveolar sounds, ③ MLL-P and lingual movement. Materials and Method : Twenty-two 4-year-old children participated as subjects in the study: a control group of 11 normal children and an experimental group of 11 children who were previously diagnosed as having ankyloglossia. They were measured for lingual function (lingual length, lingual movement) and the performances of speech articulation. Results : Children with ankyloglossia displayed significantly shorter MLL-P than 4 year normal children. Experimental group displayed significantly worse lingual movement, lower PCC in Picture consonants test, and lower PCC of alveolar sounds than control group. Ther was significantly high correlation between MLL-P and lingual movement of experimental group. Conclusion : This paper describes clinical measure and functional aspects of the tongue. Such baseline analysis provides a more definitive appraisal of lingual function as well as a more objective basis for diagnosis and treatment of ankyloglossia.