Objective: To evaluate the application value of knee length compression stockings in prophylaxis of lower extremity deep venous thrombosis (DVT). Methods: The randomized controlled trials (RCTs) concerning medical compression stockings for prophylaxis of lower extremity DVT were searched from several national and international databases. Meta-analysis was performed by using RevMan 5.2 software after a literature screen for inclusion and exclusion criteria. Results: Twelve RCTs were finally included with a total of 6 049 patients. Meta-analysis results showed that the risk of lower extremity DVT occurrence was significantly reduced compared with the non-stockings control group among the long haul flight passengers (OR=0.08, 95% CI=0.03?0.22, P<0.00001); the difference in lower extremity DVT prevention had no statistical significance between knee length compression stockings group and thigh length compression stockings group among the hospitalized patients (OR=1.47, 95% CI=0.69?3.13, P=0.32); in the pooled analysis of hospitalized patients and long haul flight passengers, the risk of lower extremity DVT occurrence in knee length compression stockings group was significantly lower than that in non-knee length compression stockings group (OR=0.32, 95% CI=0.11?0.92, P=0.03). Conclusion: Knee length compression stockings can reduce the risk of lower extremity DVT in long haul flight passengers and hospitalized patients, and its efficacy is probably better than that of thigh length compression stockings. However, this requires confirmation by randomized controlled trials of large sample size and high quality.