Abstract: Objective　To explore the risk factors of obstructive hydrocephalus secondary to intracranial hemorrhage in premature infants. Methods　A total of 304 premature infants were selected who were diagnosed as sever intracranial hemorrhage (grade III and IV) by cranial bedside ultrasound admitted to our hospital from Jun. 2013 to Sep. 2014. According to whether the obstructive hydrocephalus was followed, all infants were divided into hydrocephalus group (n=59) and non-hydrocephalus group (n=185). The risk factors of obstructive hydrocephalus secondary to intracranial hemorrhage were analyzed and the lateral ventricle size was measured dynamically. Results　The univariate analysis showed the factors related with obstructive hydrocephalus were as follows: gestational age ≤ 32 weeks, birth weight < 1500g, severe asphyxia, cesarean section, RDS, neonatal infection, heart failure, PDA, acidosis, thrombocytopenia, coagulation abnormalities, and intracranial hemorrhage (grade Ⅲ or Ⅳ) (all P<0.05). Multivariate logistic regression analysis showed that acidosis, thrombocytopenia, coagulation abnormalities, gestational age ≤ 32 weeks, severe asphyxia, intracranial hemorrhage (grade Ⅲ or Ⅳ ) were independent risk factors for obstructive hydrocephalus (OR: 1.76~20.46, all P<0.05). At each time point after birth, the ratio of posterior horn of lateral ventricle was significantly higher in hydrocephalus group than that in non-hydrocephalus group (P<0.05). There were significant differences in the changes of the posterior horn ratio of left or right lateral ventricle with time in hydrocephalus group (P=0.000), increasing at 14 days and reaching the peak at 28 days after birth. Conclusions　The risk factors for obstructive hydrocephalus secondary to intracranial hemorrhage in neonates are important. Regular and dynamical monitoring of ventricle size by cranial ultrasound is needed in infants with sever intracranial hemorrhage.