Objective：To analyze the characteristics of the chemical composition of urinary calculi in Chongqing and to provide clinical evidence for prevention and treatment of urolithiasis. Methods：Totally 839 samples of urolithiasis were collected and analyzed with infrared spectroscopy and the relevant clinical data were analyzed. Results：There were 55.30% patients from the urban and 44.70% from the rural. The main components of calculi in districts with number≥40 are calcium oxalate monohydrate，dahllite and calcium oxalate dihydrate. All the calculi included 558 cases of mixed components and 281 cases of single component；the composition mode of the former was “calcium oxalate monohydrate+dahllite”，whiel the composition mode of the latter was “calcium oxalate monohydrate+dahllite+calcium oxalate dihydrate. In gender comparison，the proportion of six ammonium magnesium phosphate in female（14.81%） was significantly higher than that of male（4.61%）. In the envi－ronmental comparison，the percentages of calcium oxalate dihy－drate and dahllite in urban patients（45.67% and 61.67%） were significantly higher than those in rural patients（35.98% and 51.88%）. In the comparison between first onset and re－crudesce，dahllite in the first onset patients（56.46%） was sig－nificantly lower than that of the recurrent patients（65.35%）. In the comparison of infection，the six ammonium magnesium phosphate in the infected group（12.33%） was significantly higher than that in the non infected group（5.27%）. In the comparison of duration，dahllite in patients with long duration（63.61%） was signifi－cantly higher than that of short duration（56.18%）. Patients aged 41 to 60 years old accounted for the highest proportion of age（55.54%），followed by 31 to 40 years old（14.30%） and 61 to 70 years old（17.28%）. Conclusion：Urinary calculi in our hospital are mainly composed of mixed components，the main components of which are calcium oxalate（including calcium oxalate monohydrate and calcium oxalate dihydrate） and dahllite. Calculi with mixed components are more common than single component stones. Male patients are more than female patients，while six ammonium magnesium phosphate was more common in female patients. Urban pa－tients are more than rural patients，and calcium oxalate dihydrate as well as dahllite are more common in urban patients. Patients with the first onset was more frequent than recurrent patients，and dahllite is more common in recurrent patients. The infected patients is fewer than the non infected patients，and the six ammonium magnesium phosphate is more common in the patients with infection. Patients with short duration is more than who with long duration，and dahllite is more common in the patients with long duration. The age of patients is mainly concentrated in 30 to 70 years old.