OBJECTIVE To explore the effects of Morinda officinalis oligosaccharides on sperm product in treating infertility.METHODS The model of decreasing sperms induced by CTX in male mice was used.The mice were randomly divided into control group,model group,water extract group of Morinda officinalis,85% ethanol extract group of Morinda officinalis,Morinda officinalis Oligosaccharides crystal group.The mice were constantly treated with the corresponding drugs for four weeks.RESULTS Compared with the model group,water extract and 85% ethanol extract and Morinda officinalis Oligosaccharides crystal group all increased the number and activity of sperms.The effect of the crystal of Morinda officinalis oligosaccharides was the most strong.CONCLUSION The Morinda officinalis oligosaccharides might be the main active substance in Morinda officinalis for sperm product.