Objective To investigate the characteristics and mechanisms of ovarian benign lesions with T1 hyperintense. Methods 16 cases of ovarian benign lesions with T1 hyperintense were reviewed. They were confirmed by surgery and pathology. The MRI sequences included T1WI/TSE, T2WI/TSE and T2WI/SPAIR. The signal intensity and homogeneity of T1WI and the signal intensity of T2WI and SPAIR were observed. Results 31 lesions with T1 hyperintense were found. 17 lesions were Endometriotic cysts (T1WI: significantly high signal 16, medium high signal 1, homogeneous 12, heterogeneity 5, T2WI and SPAIR: high signal 15, low signal 2). 2 lesions were serous cystadenoma hemorrhage (T1WI: medium high signal, homogeneous, T2WI and SPAIR: high signal). 6 lesions were mature cystic teratoma (T1WI: significantly high signal, heterogeneity, high signal reduced on SPAIR). 2 lesions were goiter (T1WI: slightly higher signal, homogeneous, T2WI and SPAIR: high signal). 4 lesions were mucinous cystadenoma (T1WI: medium high signal 2, slightly higher signal 2, homogeneous, T2WI and SPAIR: high signal 3, low signal 1). Conclusion Although the signal intensity of ovary benign lesions with hemorrhagic were stronger and more homogeneous than that of protein on T1WI, but the MR signals also had overlap. More imaging features and clinical informations can help diagnose. Fat composition of ovary benign lesions were easy to confirm because of the specific signal reduction on fat suppression sequence.