In order to investigate the prevalence of lower-extremity deep venous thrombosis (DVT) and to explore its possible reasons in children patients who received neurosurgery operation. Clinical data of 4958 cases children patients with lower-extremity DVT and without the thrombosis after the neurosurgery operation from 2010 January to 2014 December in department of neurosurgery of Tian Tan hospital were collected and analyzed. 18 cases children were diagnosed with lower-extremity DVT. All of them had invasive operation of lower-extremity deep venous catheterization. The mainly primary diseases of thrombosis children were craniopharyngioma. They have longer operation time compared with those without thrombosis (P<0.05). Therefore, the causes of DVT in neurosurgical children involve not only deep venous catheter-related but also neurological primary disease and operation time.