Acute appendicitis is the most common surgical disease of acute abdomen But the diagnosis of acute ap-pendicitis is often difficult and not in frequently operation for appendicitis is performed only to find a normal appendix. Various radiological examinations have been proposed to improve diagnostic accuracy of appendicitis. The purpose of this study was to improve the diagnostic accuracy of appendicitis and to decline negative exploration. High resolution real time ultransonographical examination using graded compression was performed in 57 consecutive patients who were clinically suspected of appendicitis. Autors analised ultransonographical surgical and clinical follow up findings. The results were are follows : 1. Ultrasonographical finding of acute appendicitis was visualization of appendix as a tubular structure with one bline end or target phenomenon. 2. Hypoechoic area over the appendix was thought to be a sign of periappendiceal abscess. 3. the sensitivity of US diagnosis of acute appendicitis in this study was 92.8% with a specificity of 93.1% The overall accuracy was 93.0% 4 In control group of 50 individuals the abnormal appendix was not visualized. 5. In cases of clinically suspected appendicitis the US evaluation with graded compression technique is very accurate and effective exmination.