Objective To explore the risk factors of venous thrombosis associated with totally implantable venous access ports system（TIVAPS）, and to provide references for formulation of nursing plans of TIVAPS. Methods Totally, 278 breast cancer patients who were on chemotherapy through TIVAPS were retrospectively included and such data as the incidence of TIVAPS-related venous thrombosis, potential factors associated to venous thrombosis were collected. Unconditional Logistic regression analysis was run to explore the risk factors of TIVAPS-related venous thrombosis. Results The incidence rate of TIVAPS-related venous thrombosis was 31.3% （n=87）, with 27.3% developing asymptomatic thrombus and 4.0% developing symptomatic thrombus.The patients who developed hypercoagulable states, had first stage cancer, and received high-density chemotherapy regimen of ddAC-ddT or FAC-T presented significantly higher incidence rate of thrombosis; the 4 factors contributed to TIVAPS-related venous thrombosis（P＜0.05,P＜0.01）. Conclusion The breast cancer patients had high incidence rate of TIVAPS-related venous thrombosis, which was associated to hypercoagulable states, advanced clinical stages and chemotherapy regimens.Patients at high risk should be closely monitored in an effort to reduce incidence rate of TIVAPS-related venous thrombosis.