Novel series of 14 (urea and thiourea) derivative compounds were prepared from reaction of urea and thiourea with aromatic amine compounds (homocyclic and heterocyclic), in addition to preparation of 6 Schiff bases (C=N) compounds that were prepared from reaction of some derived compounds with benzyldehyde in this study. All the 20 prepared compounds were characterized according to F.T.I.R. spectra, purities were examined by T.L.C., and the melting points were measured to identify each of them. From November 2005 through March 2006, a sample of (urine and sera) from 200 patients suffering U.T.I. and urinary stone attending (Diwaniya Teaching Hospital, Pediatrics and Gynecology Teaching Hospital, Health Centers and Private Clinical Laboratories) in Diwaniya, another sample was collected from 100 healthy persons as a control group. The inhibition activity was measured for each of 9 commercially used antibiotics, and for the all prepared compounds in vitro against Proteus bacteria isolated from patients under this study and identified by valid laboratory methods (Api-20E method). From (renal and bladder) 13 stones were collected from patients to detect the type of each stone by qualitative chemical analysis. Also the level of blood urea, serum uric acid, random blood sugar, serum creatinine and serum calcium, was measured for all samples in this study. This study shows the following results: "Bacterial growth for Proteus and other kind of bacteria were found in 138 patients out of the 200 (69 %), while Proteus spp. was isolated from 23 representing by 16.66 % of Proteus spp. out of the 138 patients of U.T.I.. Results of biochemical tests showed that Proteus mirabilis was found in 21 isolates with 91.3 %, and Proteus vulgaris in 2 isolates with 8.7 %. " Erythromycin was found to have the lowest inhibitory activity against Proteus spp. isolates with a percentage of resistance 86.9%, while Gentamycin have the highest inhibitory activity with a percentage of resistance 4.3 %. In bacterial sensitivity test among the 9 antibiotics was commonly used in this study. "The prepared compounds showed inhibitory activity against growth of isolated Proteus spp. in (19 out of 20) compounds, [N-(5-phenyl-1,3,4-thiadiazole)-2-ylthiourae] shows the highest inhibition activity with a diameter of inhibition zone 30 mm., while the [ N-pyridine-4-ylurea] shows no such activity in the same concentration, as compared with Gentamycin antibiotics which shows 18 mm diameter of inhibition zone. " Struvite stones were commonest type of stones in patients with 61.5 %, followed by apatite carbonate stones with 30.7 % then mixed stones with 7.85 %. "Statistical analysis shows a significant difference (P < 0.05) of the levels of blood urea, uric acid, serum creatinine and serum calcium for the patients when compared to that of control group. While no significant difference (P > 0.05) is observed or the R.B.S. level between the same groups.