Abstract: Effects of AnsiP-S (1-MCP), a new type of preservative, on physiology of postharvest senescence in kiwifruit were investigated. The harvested ‘Jingkui’ kiwifruit (Acitindia deliciosa cv. Jinkui) and ‘Miliang No.1’ kiwifruit (Actinidia deliciosa cv. Miliang No.1) fruits were treated with AnsiP-S (2.5 kg fruit per AnsiP-S chip, the effective concentration of 1-MCP was 1 mg/L), then the fruits were stored at (5±1)℃. During fruit storage, respiration rate, cell membrane permeability, malondialdehyde (MDA) content, activities of active oxygen scavenging enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), contents of endogenous antioxidant substances such as ascorbic acid (AsA) and glutathione (GSH) were determined. The results showed that compared with the control fruits, the treatment with AnsiP-S (2.5 kg fruit per AnsiP-S chip) lowered respiration rate and delayed the respiratory peak of kiwifruit, kept higher activities of SOD, POD and CAT, and higher contents of AsA and GSH, decreased MDA content, and delayed an increase of cell membrane permeability. There were lower MDA content and cell membrane permeability of ‘Miliang No.1’ kiwifruit compared with ‘Jingkui’ kiwifruit. During fruit storage at (5±1)℃, ‘Jingkui’ kiwifruit tended to be more easily senescent compared with ‘Miliang No.1’ kiwifruit. AnsiP-S treatment can delay the senescence of ‘Jinkui’ kiwifruit and ‘Miliang No.1’ kiwifruit, and prolong fruit storage period.