Abstract: A pair of treatment underpants includes a body fitting and a testicles supporter. The body fitting, which is adapted for being worn at a groin portion of a wearer, has a wearing cavity, a waist opening, and two leg openings. The testicles supporter is provided within the wearing cavity of the body fitting at a position that when the body fitting is worn, the testicles supporter is adapted for supporting testicles to keep the testicles spacing apart from a body of the wearer so as to prevent a body temperature of the wearer directly transmitting toward the testicles.