Male infertility is a stressful and frustrating problem for the society, but a number of male infertility treatments are available as traditional Chinese medicine strategies which have been tried with variable success, while evidence is still limited on whether-or how much-herbs or supplements might help increase fertility, so the aim of this study was to investigate if the oligosaccharides extracted from Morinda officialis, a Chinese herb, is the active constituents to the fertility. In this study, we prepared the H2O2-demaged human sperm, cocultured with the oligosaccharides in vitro, then observed the changes of the DNA using confocal micro-Raman spectroscopy, and comparative analysis the differences of the spectra of different treated groups. The results showed that the oligosaccharides extracted from Morinda officialis can keep the "Raman fingerprints" of the human sperm DNA almost the same as those of the control groups, but very different from the H2O2-induced groups, especially the intensity of bands at 787, 993, 1094, 1254, 1340, 1376, 1421, 1443, 1487, 1577 and 1662cm(-1) which could be as potential targets for the drugs finding, and further principal component analysis was successfully used to classify the Raman spectra of normal control and model groups. This results suggested that the oligosaccharides can protect the DNA of human sperm from being damaged by H2O2, and which was one of the active constituents of Morinda officialis on treating infertility. It was also demonstrated that Morinda officialis as a tonifying and replenishing natural herb medicine can be used to enhance reproductive functions, and the Raman spectroscopy could be an applicable technology for screening active components in vitro from herbs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.