OBJECTIVE To provide a reference for the formulation of the antithrombotic treatment regimen of children with lower extremity deep venous thrombosis （DVT）. METHODS The clinical pharmacist participated in the antithrombotic treatment of a child with purpura nephritis complicated with lower extremity DVT and formulated an individualized dosing plan for the child. Considering that the child was readmitted to the hospital when DVT of the lower extremities did not relieve after anticoagulation therapy， it was recommended that thrombolytic therapy （Enoxaparin sodium injection 30 mg， q2 h， i.d.） be initiated after joint consultation by clinical pharmacists and physicians； catheter thrombolysis and thrombolytic drug therapy were simultaneously performed （intravenous infusion of 200 000 units of Urokinase for injection， per day）； great attention should be paid to the occurrence of adverse drug reactions in children， and the changes in coagulation indexes of the children should be monitored. For long-term anticoagulation therapy after discharge， clinical pharmacists recommended oral Rivaroxaban tablets 10 mg， qd， and adjusted the dose according to the weight change of the child. RESULTS The clinician adopted the pharmacist’s recommendations. After drug thrombolytic therapy， the child’s coagulation indicators returned to normal， the symptoms of lower extremity DVT improved significantly， and there were no adverse events of bleeding or other thrombotic events after discharge. CONCLUSIONS Clinical pharmacists can assist clinicians in formulating individualized treatment plans for children based on their expertise in pharmacy to ensure the rationality of medication use in children， which helps ensure the effectiveness and safety of medication for children.