The expression of hypoxia inducible factor-1 alpha (HIF-1α) and its relationship to apoptosis in tissues around cerebral bleeding loci was studied. The expression of HIF-1α and apoptosis in 37 samples of tissues around cerebral bleeding loci and 9 samples of normal cerebral tissues was assessed by immunohistochemical straining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling methods. In 37 tissue samples around cerebral bleeding loci, the positive rate of the HIF-1α expression was 40.6 %. Especially in the patients with amount of bleeding>60 ml, the positive rate (88.9 %) of the HIF-1α expression was significantly higher than those with the amount of bleeding ranging from 30—45 ml or 45—60 ml (P<0.05). The expression of HIF-1α was increased as the amount of bleeding and operative time increased (P<0.05). There existed a positive correlation between HIF-1α labeling index and apoptosis index (n=12, r=0.56, P<0.01). These results suggested that the expression of HIF-1α was closely related with the time of hemorrhage and the amount of bleeding, and could induce the apoptosis of neurons. The expression of hypoxia inducible factor-1 alpha (HIF-1α) and its relationship to apoptosis in tissues around cerebral bleeding loci was studied. The expression of HIF-1α and apoptosis in 37 samples of tissues around cerebral bleeding loci and 9 samples of normal In 37 tissue samples around cerebral bleeding loci, the positive rate of the HIF-1α expression was 40.6%. Especially in the patients with amount of bleeding> The positive rate (88.9%) of the HIF-1α expression was significantly higher than those with the amount of bleeding ranging from 30-45 ml or 45-60 ml (P <0.05). The expression of HIF-1α was There was a positive correlation between HIF-1α labeling index and apoptosis index (n = 12, r = 0.56, P <0.01). These results suggest that the exp ression of HIF-1α was closely related with the time of hemorrhage and the amount of bleeding, and could induce the apoptosis of neurons.