Objective To explore the features of subarachnoid hemorrhage (SAH) manifested as crescentshaped high density changes on brain CT.Methods The clinical data of 32 eases of tSAH similar to acute subdural hematoma ASDH were retrospectively analyzed.Results 2 cases of 3 receiving operation procedure were cured and 1 was slightly disabled.28 cases of 29 receiving non-operation treatment were cured and l was slightly disabled. Conclusion Because sometimes tSAH is featured as crescent-shaped high density image on brain CT,which will have a better effect through non.operation,so it is easily misdiagnosed as ASDH.