Objective To use contrast-enhanced ultrasonography(CEUS) to identify the characteristics benign and malignant of complex cystic and solid breast mass, and decides whether to perform ultrasound-guided biopsy. Methods From January 2020 to January 2021, retrospective study was performed in 74 patients who were pathologically confirmed or followed up for at least one year. Combined with the results of pathology and follow-up, the characteristics of conventional ultrasound and CEUS and the diagnostic performance of malignant breast cystic and solid masses were analyzed. Ultrasound-guided biopsy cases were counted in conventional ultrasound and CEUS separately. Result among the 60 cases confirmed by pathology, 45 were benign nodules, and 15 cases were malignant nodules. There is a statistically significant difference to differentiate the benign and malignant breast complex cystic and solid nodular with CEUS focused on enhancement, enhancement range and solid components beyond the basilar part (p<0.05). CEUS could improve the sensitivity of diagnosis in malignant breast cystic and solid complex mass. 25.7% cases had been changed the decision for ultrasound-guided breast nodule biopsy with CEUS, however CEUS would not change the decision for biopsy in suspected malignant breast complex cystic and solid nodular. Conclusion CEUS plays an important role in differentiating benign and malignant breast complex cystic and solid masses, and provide a new method to make decision for biopsy.