[Operation steps] Adult male SD or Wistar rats, weighing 250-300g, are anesthetized with diazepam 5mg/kg and ketamine 50mg/kg intramuscularly. The bladder is cut longitudinally and a round piece of human bladder stone is inserted. (Crush the stone in advance, file it into a sphere with a diameter of 2 to 3 mm with a file, wash it with water, soak it in 95% ethanol for 24 hours, put it in 70% ethanol for disinfection, and set aside. Blot dry before use, and weigh accurately. Generally about 25mg). Carefully reared after surgery, the weight of the stones increased after 4-10 weeks. The effect of the drug is evaluated by the weight of the stone and the percentage increase. It is also possible to wash the lead, zinc, phosphorus and other foreign materials with clean water, soak in 95% ethanol for 24 hours, and put in 70% ethanol for disinfection. The foreign bodies are all made into round fragments of a certain weight and a certain diameter. The foreign bodies are implanted into the bladder in the same way. Generally, bladder stones can form after several weeks.