A portable toilet comprising a toilet bowl and a paper-made surrounding shield. The surrounding shield is made from a rectangular paper board which has three folding lines dividing the paper board into four equal quarters serving as two lateral walls, a door board and a rear wall of the surrounding shield. An upper half of each folding line is cut open to form a fissure. The paper board further has a transverse middle folding line at which an upper half of each quarter can be folded outward. A male and female fastening belt set is disposed at each fissure to support the four walls upright. A male and female fastening belt set is disposed at the door board of the surrounding shield for closing the door board. The toilet bowl is made by means of cutting a hard thick paper board into a square body with four close faces. Reinforcing ribs are disposed on outer faces of the four walls for strengthening the toilet bowl. Two hook members are disposed on inner faces of the toilet bowl for hooking a plastic bag to contain excretion. A seat pad board integrally extends from upper edge of each of two opposite walls and is cut with arch notch to suit the hip portion of a user. The seat pad board is foldable toward the other to be supported on the upper edges of the other two opposite walls for the user to sit thereon.