Abstract: Objective To observe the accuracy of ultrasound-guided biopsy and intraoperative frozen tissue biopsy in the diagnosis of breast masses. Methods A total of 138 patients with breast masses admitted in our hospital from June 2018 to June 2019 were enrolled in the study. Ultrasound-guided needle biopsy and intraoperative rapid frozen biopsy were performed on all subjects. The paraffin pathological examination results were used as the gold standard to compare the difference between ultrasound-guided biopsy and intraoperative frozen tissue biopsy in the diagnosis of breast masses. Results Sixty-two cases(44.93%) were diagnosed as malignant tumor, 53 cases(38.41%) as benign tumor and 23 cases(16.67%) as non-tumor. There was no significant difference between the diagnostic specificity of intraoperative frozen tissue biopsy(96.05%) and ultrasound-guided biopsy(90.79%, χ²=1.713, P=0.191), while the diagnostic sensitivity(93.55%) and accuracy(94.93%) of frozen tissue biopsy were significantly higher than those of ultrasound-guided biopsy(80.64% and 86.23%, χ²=4.593, 6.114; P=0.032, 0.013). Conclusion Compared with ultrasound-guided biopsy, intraoperative frozen tissue biopsy has more advantages in reducing the missed detection rate of breast malignant tumors and improving the diagnostic accuracy of breast mass characteristics, which is worthy of clinical application.