Abstract: As one of the long-term intravenous therapy tool, Peripherally Inserted Central Catheters (PICC) has been promoted widely in clinic. However, it would also bring a series of complications. Catheter related thrombosis is one of the most common and serious complication, which would bring many undesirable consequences, such as increasing the hospitalization time and expenses, and would even cause pulmonary embolism. Thus, we should take prophylactic thrombosis measures effectively and reduce its harmful effects. Risk assessment is the key to prevent thrombosis. This paper has reviewed the research status of risk factors and risk assessment tool of catheter related thrombosis, aiming at providing references for clinical practice.