CaWO
4 nano-powders were synthesized in micelles. Transmission electron microscopy (TEM), X -ray diffraction (XRD) and TG-DSC were utilized to characterize the shape, size and structure of the obtained products. The results show that low-dimensional CaWO
4 nano-materials can be prepared through two different systems of surfactants (CTAB and OP-10/KH-B92). The formation mechanism of colloid and the growth mechanism of CaWO
4 nano-powders were also discussed.