Abstract: Cerebral thrombus model was duplicated by applying cold light to middle cerebral artery to induce thrombus in rats, and the effects of urokinase (UK) and an extract of Whitmania pigra Whitman were observed. The results showed that severe edema， infarction in cerebrum and neuro - behavior disorders developed 24 hours after thrombus induction, and UK and the extract of Whitmania pigra could mollify these injuries. The extract of Whitmania pigra could decrease the extent of cerebrum edema by 29% and the infarction area by 45% (5.78%±0.88% vs 10.51 %±2.37% ,P＜0.01) as compared with untreated model group. It suggested that the extract of Whitmania pigra might be used to treat the injuries from cerebral thrombus, and the Photo - chemically induced rat model of cerebral thrombus was successful.