The activity of indole acetic acid oxidase (IAAO), polyphenol oxidase (PPO) [catechol oxidase] and peroxidase (POD), and the relationship between enzyme activities and rooting capacities of Broussonetia papyrifera cuttings was studied. The activity of IAAO was increased and reached its first peak at the 10th day, then it decreased slightly following an increase at the 20th day until its second peak at the 25th day. 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 slowly and reached the peak at the 20th day, and the changes were not remarkable during the following days. According to the relationship of root development and the three enzymes, the rooting processes can be divided into three phases: callus formation, root induction and root elongation. The activities of the three enzymes were mounting up during callus formation phase, and IAAO and POD reached the peak during the root induction phase. The activities of IAAO and POD decreased and the activity of PPO increased during the root elongation phase.