Abstract: A paper drinking straw is provided with an elongated member of paper having two short sides and two long sides wherein one long side includes a first joining strip and the other long side includes a second joining strip; a piercing segment at a position of the first joining strip superimposed on the second joining strip; and a cutting segment at one short side and including a first cutting edge connected to one long side, a second cutting edge connected to the first cutting edge and inward inclined relative to the first cutting edge, a third cutting edge connected to the second cutting edge and outward inclined relative to the first cutting edge, and a fourth cutting edge interconnected to the third cutting edge and the other long side. The first joining strip is superimposed on the second joining strip and secured thereto to form the paper drinking straw.