Color ultrasound is a form of sonographic examination and is now a more clinically relied upon diagnostic aid in major hospitals, but it is not the same as our color television. Many patients in the clinic have doubts when doing color ultrasound examination, seeing the screen are black and white, they think their examination is not color ultrasound, why color ultrasound is without color. Color ultrasound is able to display the direction of blood flow or the relative speed of blood flow in real time with color images on top of 1D and 2D. According to international standards, the blood flow map on color ultrasound is composed of three base colors: red, blue and green. And it is stipulated that the red blood flow represents the direction toward the probe and the blue blood flow represents the direction away from the probe. Also, the speed of blood flow is expressed according to the brightness of the color. On top of the ultrasound report. After the general description of the tissue and organs or abnormalities, “CDFI” is added to the report, which describes the direction and speed of blood flow and other shunts, especially in cardiovascular applications. In clinical practice, when differentiating benign and malignant tumors, the blood flow inside the tumor can also help to identify the nature of the tumor. Ultrasound is equivalent to the clinician’s eyes, mainly helping the doctor to analyze and diagnose the disease, and to observe and determine the progress of the disease safely and effectively on a regular basis.