A clinical and radiological observation was made on 167 cases of urolithiasis among the number of 150 patients during 1 year and 6 months rom June, 1981 to November, 1982. The results were summerized as follows. 1. There were 101 man and 49 women, a ratio of 2 : 1. The ages of the patients ranged from 2 to 74 years, showing the highest incidence in 31 to 60 years (68.1%). 2. Locational distributions of urolithiasis were 80 cases (47.9%) in the ureter, 66 cases (39.5%) in the kidney, 11 cases (6.5%) in the urethra and 10 cases (5.9%) in the bladder. 3. Among the 66 cases of renal stone, pelvis stone was 55 cases (83.3%) with staghorn types in 23 cases (34.8%), and calyceal stone was 11 cases (16.6%). 4. The location of ureteral stone was 47.5% in lower, 40% in upper ureter and 12.5% in mid-ureter. 5. The location of urethra stone was 82% in the anterior urethra and 18% in the posterior urethra. 6. The chief complain of urolithiasis was flank pain in 59.2%, gross hematuria in 20.3%, renal colic in 13.1%, dysuria in 8.3%, nausea and vomiting in 4.7%, and sudden stoppage of urine stream in 3.5%. 7. On urinalysis, gross hematuria was found in 54.4%, pyuria in 28.7%, bacteriuria in 23.3%, microscopic hematuria in 18.5% and normal in 7.1%. 8. The size of urinary stone was 0.6-0.2cm in length in 105 cases (62.8%). 9. On I.V.P. study of renal stones (66 cases), mild and moderate hydronephrotic changes were detected in 38 kindneys (57.5%), and the relationship between the urinary stasis and renal stone was relatively good. 10. On I.V.P. study of ureteral stones (80 cases), mild to severe hydronephrotic changes were detected in 64 kidneys (80%). 11. On K.U.B. film, paralytic ileus was found in 25 cases (14.9%). 12. Among the urinary stones, the radiolucent stone were detected in 8 cases (4.7%). 13. Urinary stones disappeared in 11 cases (6.5%) spontaneously or medical treatment.