Sugarcane molasses was pretreated with different clarification methods and the components and properties of molasses after clarification were analyzed. Results showed that the contents of colloid and ash decreased and reducing sugar increased evidently. Moreover, the reducing power and free radical-scavenging activity on DPPH of molasses were determined after clarification. It was showed that the best pretreatment procedure was diluting the molasses by water with the water-molasses mass ratio of 6; flocculating the diluted molasses with poly(acrylamide); and then centrifugating the mixture for further acidolysis. Using this procedure, the highest reducing sugar of the molasses reached and the loss of anti-oxidative activity of molasses was the lowest.