In order to clarify the effect of AMF on the resistance of muskmelon to compound stress, and to explore its physiological mechanism, we investigated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and the antioxidant activities of melon under low light and salt stress by pot experiment in greenhouse. The results showed that: （1） the growth of melon seedlings was significantly inhibited. The plant height, the dry weight and the fresh weight were significantly reduced. Soluble protein, soluble sugar, proline, malondialdehyde (MDA) contents and antioxidant enzymes activities (SOD, POD and CAT) in melon seedlings under low light and salt stress were higher than those in control group. （2） The inoculation with Glomus could significantly promote the growth of muskmelon seedlings, and the rate of mycorrhizal infection was negatively correlated with salt stress with the extension of stress time.（3） The inoculation with Glomus improves the physiological parameters of inoculated seedlings compared with nonAM seedlings; the contents of soluble sugar, soluble protein, starch, proline and antioxidant enzymes activities (SOD, POD and CAT) increased significantly, while MDA content decreased, and mycorrhizal infection rate with stress duration was negatively correlated with the salt concentration; the contents of SOD and POD in leaves were more active than those in roots, while CAT activity was less than that in roots. We propose that AM symbiosis can protect melon plants from low light and salt stress by improving their antioxidant activities and bidirectional transport of carbohydrates.