Abstract: Field experiment was conducted to explore the effects of foliar-spraying prohexadione calcium on the physiological characteristics and pod yield of peanut (Arachis hypogaea L.). Results showed that chlorophyll contents and thickness of leaves were significantly increased, and photosynthesis was improved by using prohexadione calcium. The activities of SOD, POD and CAT were enhanced, and the soluble protein contents of leaves are increased as well. While, there were little effects on activity of root and the contents of MDA of leaves. Spraying prohexadione can control growth of leaf and stem, increase the number of pods per plant, and enhance the pod yield. In general, the effects of prohexadione calcium on peanut growth and developments are better than spraying paclobutrazol (PP333).