Abstract ：Purpose: To assess the liver tissue elasticity of breast cancer patients treated with TAC combined chemotherapy by ultrasonic tissue dispersion quantitative analysis, and to provide an effective quantitative ultrasonic method for early assessment of liver injury. Materials and Methods: This study is a prospective controlled study. 38 healthy people were selected as the control group, and 35 patients with breast cancer confirmed by pathology who needed 6 cycles of TAC combined chemotherapy were selected as the chemotherapy group. Routine liver ultrasonography and tissue dispersion quantitative measurement were performed to get the following data: liver fibrosis index (LFI), the percentage of blue area (%AREA), the mean strain (MEAN). Biochemical test were also performed to get liver function data including glutamate transaminase (ALT) and aspartate aminotransferase (AST). The data were compared between two groups before chemotherapy, and among the different chemotherapy cycles. Correlation analysis was performed between biochemical index and elastic index including LFI, %AREA and MEAN. Results: 1. There was no significant difference between the two groups before chemotherapy. In the chemotherapy group, compared with the data before chemotherapy, LFI and %AREA increased (P<0.05), and ALT, AST has a tendency to incresase, but AST was still within normal limit and ALT almost reached upper normal limit after the 2nd cycle. After the 4th cycle and the 6th cycle, MEAN decreased while %AREA and LFI increased（P<0.05）. Also, ALT and AST increased (P<0.05). In the chemotherapy group, after the 4th cycle, MEAN decreased while %AREA and LFI increased（P<0.05）and ALT, AST increased（P<0.05） compared to the data after the 2nd cycle. After the 6th cycle, MEAN decreased while %AREA and LFI increased（P<0.05）and ALT, AST increased（P<0.05） compared to the data after the 2nd cycle and after the 4th cycle. 2. Removing the effect of chemotherapy cycles，LFI was positively correlated with ALT（r=0.341, P=0.000）, %AREA was positively correlated with ALT（r=0.261，P=0.002）, and MEAN was negatively correlated with ALT（r=-0.215, P=0.011）. Conclusion: The technology of ultrasonic elastography tissue dispersion quantitative analysis can be used to assess the elastic characteristics of liver tissue quantitively in breast cancer patients undergoing chemotherapy. LFI, %AREA and MEAN are expected to be effective indexes to evaluate early liver injury in patients of breast cancer with TAC combined chemotherapy quantitively.