A novel method for controlled synthesis of crystalline molybdenum dioxides nanowhiskers (whisker-MoO2) by using moderate reductive and precursor ion under hydrothermal conditions is reported. The result shows that the as-obtained samples have a monoclinic structure,and the whisker-MoO2 is composed of nanowires with diameters of ca. 20 nm. Formation of whisker-MoO2 was through a typical precursor-reduction process, in which cetyltrimethylammonium bromide (CTAB) served as a cationic surfactant and acetone as a reductant. The electrochemical behavior of whisker-MoO2 was studied.