The present invention relates to pure oxygen-containing soju and a manufacturing method thereof. The invention provides the pure oxygen-containing diluted soju, which has excellent economy and shows a greatly reduced degree of a hangover after drinking thereof, because the amount of lost oxygen is minimized by injecting the largest possible amount of oxygen while preventing the release of oxygen using a method of injecting oxygen, and the amount of dissolved oxygen in the soju is maximized by injecting fine oxygen bubbles at low temperature, as well as a manufacturing method thereof.