OBJECTIVE: To observe clinical efficacy of urinary kallidinogenase in the treatment of acute cerebral watershed infarct (WSI). METHODS: 128 patients with WSI were randomly divided into control group and treatment group, each of the 64 cases. Control group was given Shuxuening 15 ml added into 0.9% Sodium chloride 250 ml, ivgtt, qd; treatment group received urinary kallidinogenase 0.15 PNA added into 0.9% Sodium chloride 100 ml, ivgtt, qd. Both groups were treated for consecutive 14 days. Neurologic impairment score (NIHSS) and clinical efficacy were observed in 2 groups before treatment and 3, 7 and 14 days after treatment. The blood specimens were collected after 7 and 14 days treatment, to determine serum levels of TCC. RESULTS: After treatment, NIHSS and total effective rate of treatment group were significantly higher than those of control group, with statistical significance (P<0.01). There was no statistical significance in TCC between 2 groups before treatment (P>0.05); 7 days after treatment, TCC level of 2 groups increased significantly, to 14 days, and a declive; the treatment group was higher than the control group, with statistical significance (P<0.05). CONCLUSIONS: Urinary kallidinogenase can improve clinical efficacy of WSI significantly, and promote neurologic impairment symptom and TCC levels.