A fully characterised natural rubber latex was subjected to mechanicaldegradation by stirring at intervals. The resistance to oxidative degradation of the differentsamples were studied by measuring the Plasticity retention indices (PRI). The results show that there is an enhancement of the PRI from 57% for the undegradedrubber to 79% for the one-hour degraded sample. Further degradation resulted in decreaseof PRI as time of degradation increased. Therefore

the one-hour degraded sample is aspecial rubber with high oxidation resistance which is of great importance in engineering.