The fundamental vocal frequency is produced by simple vibration of the whole length of the vocal folds and is one of the most important single parameters in determining the eventual characteristics of the voice. The authors measured external laryngeal height and fundamental frequency in third decade adults and about 10-year old children in order to use them as the base of diagnosis and treatment of laryngeal diseases. Results were as follows : 1) Mean external laryngeal height in adults was 37.8±3.15mm in male and 31.01±3.18mm in female(p<0.01). 2) Mean fundamental frequency in adults was 118.1±10.60Hz in male and 220.36±13.75Hz in female, and the difference was statistically significant(p<0.001). 3) Mean external laryngeal height in children was 27.28±2.77mm in male and 25.93±5.00mm in female, and the difference was not statistically significant. 4) Mean fundamental frequency in children was 225.0±15.79Hz in male and 239.25±15.92Hz in female, and the difference was not statistically significant. 5) In adults, the external laryngeal size was correlated with fundamental frequency and it was statistically significant(r=0.43).