We investigated a surface modification method for potassium chlorate (PC) characterized by great combustibility and for potential usage as a gas generator with inorganic minerals such as talc etc. Samples modified by a wet method using a binder and those by a dry method using ordered mixture were conducted for their surface modification under a scanning transmission electron microscope (STEM) and by mapping according to element for element analysis with an energy dispersive spectrometer (EDS). Mapping by element suggested that the dry method enabled a relatively uniform, thin tare coating on the surface of the PC. The results of the mechanical energy sensitivity tests of the oxidizer composite containing the surface modified (desensitized) PC demonstrated formation of a low sensitivity product with a maximum friction sensitivity of over 13 times (BAM: 4.2 kgf--> over 55.2 kgf) and a maximum impact sensitivity determined by a drop hammer test of over 5 times (20 cm--> over 100 cm).