A gas regulator with a gas-amount display assembly is capable of showing an amount of gas in a gas storage device connected to the gas regulator, and the gas regulator includes a regulating assembly, a detecting assembly, and a display assembly. The detecting assembly has a touch switch and an abutting component selectively abutting the touch switch. The display assembly and the detecting assembly are separated from each other. The display assembly changes its display state according to whether the abutting component abuts the touch switch or not. With the detecting assembly and display assembly separated from each other, the regulating assembly and the detecting assembly can be disposed with the gas storage device at a safe position, and the display assembly may be disposed at a position that can be observed easily. Thus, the user can check the amount of the gas at any time.