Abstract: In order to explore the effects of exogenous MT（melatonin）,AsA（ascorbic acid）,Ca（calcium）and Si（silicon）on the low temperature resistance of Luffa acutangular（Linn.） Roxb. seedlings, exogenous substances were sprayed on the leaves of Luffa acutangular（Linn.） Roxb. seedlings at 8℃. The effects of four exogenous substances on cold resistance of Luffa acutangular（Linn.） Roxb. seedlings were studied from the aspects of seedling morphology, antioxidant enzyme activity, osmotic regulatory substances and chlorophyll content. The results showed that spraying 100 μmol/L MT, 50 mg/L AsA, 12 mmol/L Ca and 1.5 mmol/L Si on the leaves of Luffa acutangular（Linn.） Roxb. seedlings could improve the cold resistance of the seedlings, and 50 mg/L AsA had the best effect, which could not only reduce the chilling damage index, leaf conductivity and malondialdehyde（MDA）content of Luffa acutangular（Linn.） Roxb seedlings. Moreover, it could improve root activity and antioxidant enzyme activity in leaves of Luffa acutangular（Linn.） Roxb. seedlings, promote the accumulation of soluble sugar, soluble protein and proline in leaves of Luffa acutangular（Linn.） Roxb. seedlings, reduce the loss of chlorophyll content, and effectively alleviate the damage of low temperature on Luffa acutangular（Linn.） Roxb. seedlings.