The practice of Xi Sui Kung (洗髓功), also transliterated as Shih Shui Gong, has been called many things. Some refer to it by associated practices of “Iron Shirt” or “Iron Body,” for which Xi Sui Genital Weight Qi Kung is a prerequisite and accompanying practice. Other times, it is simply referred to as “Iron Crotch” and “Genital Qi Kung” or “99 Power Qi Kung” (九九神功). The traditional name, however, is simply Xi Sui Kung which means “Bone Marrow Washing” and constitutes the secret corpus of knowledge from the Indian patriarch Bodhidharma, or “Da Mo,” (which is short for “P’u Ti Da Mo,” 菩提達摩). This text will explain some of the history and purpose of Xi Sui Genital Qi Kung. At its conclusion, the reader will be given contact information to begin a correspondence course in the first level of Xi Sui Kung (1-50 lbs training).