Abstract: Objective:To explore the correlation between the T2WI characteristics with ADC value and the expression of Ki-67 in young women with invasive breast cancer. Methods:Thirteen young patients (≤ 35 years old) admitted to our hospital from May 2018 to July 2019 were selected as study objects. The T2-weighted signal characteristics and apparent diffusion coefficient (ADC) values of the focus in the MRI scanning sequence were recorded in detail, and the percentage value of Ki-67 (activity of proliferating cells) was calculated by immunohis to chemistry. Results:The ADC value range of young women with invasive breast cancer was (0.78±0.08)×10^-3/mm², and the positive expression rate of Ki-67 detected was about 92%. In the focus, T2WI showed slightly higher signal and positive expression rate of Ki-67 were positively correlated, while ADC value was negatively correlated with Ki-67 within a certain range. The T2WI signal and the quantization value of ADC in the lesions were analyzed to be the factors influencing the positive expression of Ki-67. Conclusion:In young women with invasive breast cancer, the T2WI sequence signal features are mostly slightly high signal (84%) or equal (16%). With ADC value decreasing to a certain range (1×10^-3/mm²), Ki-67 presented a significant increase in positive expression. T2WI signal characteristics combined with ADC values have important reference value for diagnosis, clinical treatment selection and prognosis prediction of young female patients with invasive breast cancer.