Breast nodule grading is independent of size. 0.3*0.4cm nodules need to be graded based on signs such as the aspect ratio of the mass, shape, calcification and blood flow signal. BI-RADS grading is a benign and malignant risk assessment based on the description of the nodule in breast ultrasound, molybdenum target and other imaging examinations, and it is categorized into grades 0-6 according to the likelihood of malignancy. BI-RADS is mainly evaluated based on the presence or absence of suspicious malignant signs such as mass morphology, margins, echo type, calcification, blood flow, etc. The BI-RADS classification does not use the size of the nodule as a sign of benign or malignant. The general signs of malignancy include irregular morphology, unclear margins, hypoechoic or mixed cystic-solid echoes, small calcifications, and abundant blood flow. Those with suspected malignant signs are mostly grade 4 or 5 nodules. Patients are advised to refer to ultrasound and molybdenum reports for the grading of the nodule, or consult a specialist to analyze the specific description of the nodule in the report and follow the doctor’s instructions for further examination and treatment.