From February through July 1994, we measured nasal resistance of 220 normal children(4-14 year old) with acoustic rhinometry(Rhinoklack RK 1000 system) to evaluate the change in nasal resistance according to age. We calculated the distance and cross sectional area of the isthmus nasi, the anterior and of the inferior turbinate and nasal volume at each age in both sexes. As to the distance and cross sectional area of the I(istmus nasi) notch and the C(conchal) notch, as well as the nasal volume, statistically differences were not noted between both sexes. As the age increased, the areas and distances of the I notch and C notch, and nasal volume were increased significantly(p<0.05). There were stasistically significant differences in the I notch distance below 6-year-old children of both sexes, and in the C notch distance of below 9-year-old children in female and 12 year old children in male compared with the data of normal adults. We concluded that the nasal resistance of children is larger than that of adults and decreases with the increase of age.