Abstract: The quasi 2 static indentation (QSI) damage resistance of composite laminates was tested. Ult rasonicC2scan and SEM were conducted on QSI specimens under two given loads and the damage process was analyzed.The damage resistance of composite laminates was discussed through the initial delamination contact force f₁ and themaximal contact force f₂ . The repetitive characteristic of f₂ was confirmed by testing two kinds of materials systems. Moreover , the effect s of the test conditions ( specimens dimension and clamp hole diameter) and materialsproperties (the size of fiber , resin mat rix and plying pattern) on the maximal contact force were studied. The testresults indicate that the effect of the specimens dimension and clamp hole diameter on the maximal contact force is neglectable , materials components properties (fiber characteristic , resin characteristic and plying ways) could influence the maximalcontact force and the dent depth d₂ corresponding with f₂ is principally decided by the st rength and elongation of the fiber.