Objective: To investigate the effect of helium-oxygen mixture (He-O2) containing 60% helium on improvement of anoxia syndrome in respiratory diseases. Methods: Vital capacity (VC) and its component expiratory capacity (ERV) and inspiratory capacity (IC) were detected in non-smoking healthy volunteers before and after breathing helium-oxygen mixture and the changes were compared. Results: After breathing He-O2 containing 60% helium, VC and ERV increased enormously, while IC decreased mildly, among which the change of ERV showed significant difference (P<0.05). Conclusions: The changing tendencies of vital capacity and its components ERV and IC after breathing He-O2 containing 60% helium are consistent with those after breathing He-O2 containing 80% helium, and their changing rates are also similar, which indicate that He-O2 containing 60% helium may has the same therapeutic effect as that containing 80% helium does in clinic.