Abstract: Multiply-alkylated Cyclopentanes (MACs) was used as a base oil to prepare calcium sulfonate complex grease. The properties of liquid high molecular phenolic antioxidants (L135), benzotriazole derivative (T551), thiadiazole derivative (T561) in calcium sulfonate complex greases were studied on friction pair of steel disc and steel ball. The thermo-gravimetric analysis was carried out to evaluate the thermal stability of calcium sulfonate complex greases. The MFT-R4000 reciprocating friction and wear tester was utilized to evaluate the tribological properties. Scanning electron microscope and energy-dispersive X-ray spectroscopy were employed to analyze the worn surfaces and main chemical elements. The results show that calcium sulfonate complex greases prepared by MACs showed better thermal stability, and the compatibility of calcium sulfonate complex greases with additives was good because MACs calcium sulfonate complex greases showed better friction-reducing and anti-wear properties. The boundary lubricating film of MACs on the worn steel surface by physical absorption enhanced load-carrying ability of oil film and the tribo-chemical film containing S, N, Fe reduced the friction and wear.