Objective To investigate MRI findings of triple-negative breast cancer (TNBC) and correlation with Ki-67 index in Uygur women.Methods Totally 97 patients with pathologically confirmed TNBC were enrolled.Among them,28 patients were Uygur nationality (Uygur group;28 lesions) and 69 were Han nationality (Han group;70 lesions).MRI features of the two groups were observed and compared,and the correlation between MRI findings and Ki-67 index in Uygur group was analyzed.Results The pathological type of TNBC in Uygur group and Han group was both mainly invasive ductal carcinoma (grade 3).There was no statistical difference of Ki-67 index nor ADC value between the two groups (both P＞0.05).The Uygur patients were younger than Han patients (P＜0.05) and maximum diameter of lesions and early enhancement rate in Uygur group were higher than those in Han group (all P＜0.05).The margin and enhancement features of lesions were statistically different between the two groups (both P＜0.05).The dominated type of time-signal intensity curve (TIC) in Uygur group was wash-out type,while in Han group was plateau type (P＜0.001).The Ki-67 index was positively correlated with tumor shape and TIC type in Uygur group (r=0.464,0.606,both P＜0.05).Conclusion MRI features of Uygur women with TNBC is somewhat different from Han women,and part features are correlated with Ki-67 index.