PURPOSE: The purpose of this study was to establish the guidelines for normal splenic length by sonographic measurement. MATERIALS AND METHODS: In 481 children (age range : 2-16years, M:F=1.5:1), abdominal sonography for the purpose of health screening was carried out, and the greatest length of spleen between the dome and tip was measured. Correlation and regression analysis was used to determine whether the relationship between splenic length and a patient's age, height, weight and body surface was statistically significant. RESULTS: The length of the spleen gradually increased according to age. Correlation and regression analysis showed significant positive correlation (p<0.0001) between splenic length and age (r=0.610) height (r=0.630), weight (r=0.598), and body surface (r=0.628). CONCLUSION: From the mean values of spleen length in children, an index useful for clinical application might be derived.