A quaternary ammonium salt (QAS) was synthesized and characterized by H-1 NMR. A low environmental sensitive antistatic plasticized poly(vinyl chloride) (PPVC) was prepared by blending with QAS and poly(ethylene oxide) (PEO). The structure and properties of PPVC/QAS/PEO blend were studied by scanning electronic microscope (SEM), surface resistivity, and mechanical properties tests. The results show that the surface resistivity of PPVC/QAS/PEO (100/4.5/0) blend without PEO component can be reduced to less than 3.0 X 10(8) Omega at 65% environmental humidity, which satisfied the antistatic property requirement related to MT113-1995 of China. However, QAS, similar to other commercial antistatic agents, is much sensitive to environmental humidity. When a small amount of PEO is added, the surface resistivity of PPVC/QAS/PEO blend has a quite low sensitivity to environmental humidity and further reduces. An excellent antistatic property of PPVC/QAS/PEO blend under low humidity can be achieved. Its tensile strength and elongation at break are also improved with PEO addition. (C) 2008 Wiley Periodicals, Inc.