Abstract: The activity of indoleacetic acid oxidase(IAAO),polyphenol oxidase(PPO) and peroxidase(POD), as well as, the relationship between enzyme activities and rooting capacities of Broussonetia papyrifera cuttings was studied in this paper.The activity changes of IAAO was as follows: the activity of IAAO increased and reached its first peak at the 10th day, then it decreased slightly following an increasing at the 20th day till reached its second peak at the 25th day, afterward, it kept decreasing in the following process. The activity change of POD was the same as IAAO in the first 25 days, then mounting up over the 30th day; the activity of PPO increased tardily and reached the peak at the 20th day, and the changes was not remarkably during the following days. According to the relationship of root developing and the three enzymes, the rooting processes can be divided into there phases:callus formatting,root inducing and root elongating.The activities of the three enzymes were mounting up during callus formatting phase, and IAAO and POD reached the peak during the root-inducing phase. The activities of IAAO and POD decreased and the activity of PPO increase during the root-elongating phase.