A radial artery blood pressure waveform measuring device includes a stress sensor, a stress concentrating elastic structure, and a stress guiding elastic member. The stress sensor is in contact with a skin surface of a wrist corresponding to a position of a radial artery. The stress concentrating elastic structure is disposed on the stress sensor. The stress guiding elastic member has a top surface, a bottom surface, and at least one side surface. The bottom surface is disposed on the stress concentrating elastic structure, and an area of the bottom surface is greater than an area of a horizontal section of the stress concentrating elastic structure.