Transmission electron microscopy （TEM） was used to observe polytetrafluoroethylene （PTFE） dispersion particle microstructures. At a low accelerating voltage, TEM images, presumably of lamellar structures with hexagonal lattices and ribbon-like structures with molecules aligned in parallel, were obtained successfully for thin regions of the particles without damage by the electron beam. Furthermore, the helical structure of PTFE molecules, as predicted by X-ray diffraction （XRD）, was observed in real space.