Since opening of the Yeungnam University Hospital in June 1983 till end of 1984, total 30 cases of cerebral thrombosis were analysed clinically. Among the 30, 17 cases were given Urokinase from 60,000 to 240,000 units daily for 2-46 days. The interval from the onset to the inititiation of therapy varied from 1 hour to 17 days. Ten cases showed marked recovery and 6 cases moderate improvement. One case, in which only 120,000 units daily were administered, showed stationary course. The interval of the Urokinase untreated 13 cases was from 3 days to 18 months. Six cases were stationary, whereas 7 cases showed mild improvement. Age, sex, past history, associated diseases, and the laboratory findings are shown in the tables. Conclusion is that the earlier the therapy started, the higher the dosage used, the better of the results is obtained.