A study about the program of color Doppler to improve blood velocity estimation has been developed. Color Doppler echocardiographic images were acquired using Philips IE33 have a crucial issue the ambiguity of the offset beams when the correct velocity of the blood flow exceeds the velocity of the Nyquist limit. Therefore, velocity dealiasing is needed in quality control of color Doppler echocardiographic data to correct velocities using EDG (echodynamography) based on observer and machine interaction. The program is applied to echocardiography images of aortic stenosis subject as a technique to assess cardiovascular function. One challenging with color Doppler is correcting velocity aliasing. The observer determines the ambiguity area based on his or her knowledge. These results confirm the dealiasing and noise removing are vital elements in improving blood velocity estimation in cardiovascular diagnostic. Therefore, this study could use clinical tools based on color Doppler imaging.