[Objective] To extract and isolate the effective components from Sorbus tianschanica,and to research the hypoglycemic effects of n-Butanol part. [Methods]S. tianchanica was extracted by reflux extraction. After gradient elution,n-Butanol part was obtained. With diabetic mice induced by STZ as the model,blood glucose test was carried out. [Results]n-Butanol part in administration group had significant differences in hypoglycemic effects with that in model group(P < 0. 05),showing that n-Butanol part had certain antidiabetic functions on diabetic mice induced by STZ. And the hypoglycemic effects showed a reducing trend as the administration dosage decreased,indicating that administration dosage had positive correlation with hypoglycemic effects. n-Butanol in different parts could reduce the blood glucose of diabetic mice in different degrees. And the blood glucose value in high-dosage group(8 g /kg) reduced greatly at 2 h after administration,having great differences with that in model group(P < 0. 01). This showed that high dosage was helpful to the glucose tolerance of diseased mice,and could effectively protect against the rapid increase of blood glucose after meal. n-Butanol had no significant effects on the blood glucose of normal mice. However,the morality rates in high-and middle-dosage groups were both higher than that in low-dosage group; and the morality rate in administration group was lower than that in model group,showing that n-Butanol could promote the survival rate of diabetic mice. [Conclusions]S. tianchanica had certain effects of anti-diabetes. [Objective] To extract and isolate the effective components from Sorbus tianschanica, and to research the hypoglycemic effects of n-Butanol part. [Methods] S. tianchanica was extracted by reflux extraction. After gradient elution, n-Butanol part was obtained. With diabetic mice induced by STZ as the model, blood glucose test was carried out. [Results] n-Butanol part in administration group had significant differences in hypoglycemic effects with that in model group (P <0.05), showing that n-Butanol part had certain antidiabetic functions on diabetic mice induced by STZ. And the hypoglycemic effects showed a reducing trend as the administration dosage decreased, indicating that administration positive had with hypoglycemic effects. n-Butanol in different parts could reduce the blood glucose of diabetic mice in different degrees. And the blood glucose value in high-dosage group (8 g / kg) reduced greatly at 2 h after administration, having great differences with that in model g This was shown that high dosage was helpful to the glucose tolerance of diseased mice, and could effectively protect against the rapid increase of blood glucose after meal. n-Butanol had no significant effects on the blood glucose of However, the morality rates in high-and middle-dosage groups were both higher than that in low-dosage group; and the morality rate in administration group was lower than that in model group, showing that n-Butanol could promote the survival rate of diabetic mice. [Conclusions] S. tianchanica had certain effects of anti-diabetes.