OBJECTIVE:To explore the effect of administration timing of mannitol on efficacy and related indexes of patients with moderate cerebral hemorrhage. METHODS:Data of 280 patients with moderate cerebral hemorrhage being treated with manni-tol were divided into super-early group(65 cases),early group(97 cases)and extension group(118 cases)was analyzed retrospec-tively according to administration timing. All patients received conservative medical treatment,ntrition brain cells and other symp-tomatic and supportive treatment. Based on it,super-early group received mannitol within 6 h of cerebral hemorrhage,early group received mannitol within 6-24 h,and extension group received mannitol more than 24 h. Clinical efficacy,incidence of hematoma enlargement,mortality,incidence of continued bleeding/rebleeding and incidence of adverse reactions in 3 groups were observed. RESULTS:The incidences of hematoma enlargement and mortality in early group and extension group were significantly lower than super-early group,the differences were statistically significant (P<0.05);but there were no significant differences between early group and extension group (P>0.05). The total effective rate in early group was significantly higher than super-early group and extension group,the incidence of continued bleeding/rebleeding was significantly lower than super-early group and extension group,the differences were statistically significant (P<0.05);but there no significant differences between super-early group and extension group (P>0.05). CONCLUSIONS:Based on conventional treatment,mannitol shows better efficacy for patients with moderate cerebral hemorrhage within 6-24 h of cerebral hemorrhage than those in super-early or extension. It can reduce continued bleeding/rebleeding incidence,and has equivalent safety.