=2.5hours) This paper compared the value of bilirubine before operation and the declining value ,velocity and percentage of bilirubine after operation on two groups. Results: There is no significant difference of the level, percentage of bilirubine declining before and after blood-exchange (p>0.05). But under the certain blood-exchange quantity, the shorter the operation time, the more blood quantity were extracted out and the faster the decreasing of bilirubine (p<0.05). Conclusion: The results suggest that there is no significant difference on the relationship of the time of blood-exchange with the final level of bilirubine in blood (p>0.05). But under the certain blood-exchange quantity, the shorter the time of blood-exchange, the faster the decreasing of bilirubine. Key words: neonate, the time of blood-exchange, bilirubine " v:shapes="_x0000_s1026">0675