Blood flow before and after end-in-end and end-to-end anastomosis of common carotid arteries in 35 rats was measured and compared quantitatively right after operation, 1 to 3 days later, 7 to 14 days and 57 to 58 days following operation. The results in each group showed no significant difference statistically. Being much easier to master and time saving, end-in-end anastomosis has become a favoured technic.