PA66 reinforced with potassium titanate whisker (TKW) treated with silane coupling agent were prepared using a twin-screw extruder. The quasi-static and dynamic mechanical properties were investigated. Addition of 40 wt % TKW to PA66 improves all the investigated properties. The high-speed dynamic tests with TKW[PA66 were carried on split Hopkinson pressure bar (SHPB). The loading pulses in SHPB experiments were precisely controlled to ensure that the composite specimens deformed at a nearly constant strain rate under dynamically equilibrated stress during dynamic compression. The constitutive curves and equations at high strain rates have been obtained. TKW/PA66 composites show 20-100% increase on reference modulus and 20% increase on compression strength. (c) 2005 Elsevier Ltd. All rights reserved.