Yin ultrasound and color ultrasound are different in terms of examination items, examination methods and preparation before examination. 1. Examination items (1) Yin ultrasound: it is suitable for observing the pelvic organs in the small pelvis, and is used for ovulation monitoring, confirming the diagnosis of ectopic pregnancy, uterine occupational diseases, and the diagnosis of polycystic ovary syndrome and chocolate cysts. (2) Color ultrasound: It is mostly used for vascular diseases, abdominal organs lesions, heart diseases, eyeballs and other small organs lesions, prostate and seminal vesicles examination, and obstetrics and gynecology disease diagnosis. 2. Examination method: Yin ultrasound is to put the ultrasound probe into the vagina or rectum for ultrasound diagnosis; while color ultrasound is to put the probe on the surface of organs for examination. 3. Preparation before examination: Yin ultrasound can be examined without holding urine; while color ultrasound needs to be carried out in a state of full bladder, so color ultrasound needs to hold urine. There are many differences between negative ultrasound and color ultrasound, and the examiner should pay attention to the preparation before the examination.