Abstract: In order to solve the problem that broccoli could not be precooled in time, 1 μL/L 1-methylcyclopropene (1-MCP) was used to treat broccoli at 20±2 ℃ for 6 h. The effects of 1-MCP on the preservation of broccoli were studied by measuring the basic physiological and biochemical indexes and related antioxidant enzyme activities. The results showed that 1-MCP treatment could significantly improve the sensory quality of broccoli during one day storage, inhibit the respiratory intensity, maintain a higher total glucosinolates content, and improve the activities of POD, APX and SOD. 1-MCP treatment and precooling and cold storage treatment stimulated H₂O₂ production and inhibited CAT activity. The results of principal component analysis showed that color difference a^*, respiratory intensity, hydrogen peroxide content, glucosinolates content and CAT activity were the key indexes in broccoli preservation. This study showed that 1-MCP treatment could achieve good preservation effect immediately after the broccoli was harvested, which could play a substitute role when it could not be precooled in time. It would provide a theoretical basis for the cold chain transportation and industrialization of broccoli.