Uremic Stomatitis can be happened by effect of improvement of concentration of ureum in saliva of effect of height of level of ureum blood. The aim of this cross sectional research to know influence of rate of ureum of blood with the happening of uremic stomatitis at patients chronic renal failure (CRF). As much 36 sample taken away from patient of CRF in RS. Wahidin Sudirohusodo Makassar. Rate of Ureum of blood known from result of inspection of laboratory enclosed at card of patient status, while stomatitis conducted by a direct inspection at patient of persuant to location, type of stomatitis. Analyzed data with of X2 test, t test, Logistic Regression and Simple Linear regression at a=0.05 contructively Program SPSS/PC(-) version 9. Result of research that mean of rate of ureum blood = 170.3889 mg/dL, there relation and influence have a meaning between rate of ureum of blood to the happening of uremic stomatitis at patients CRF (p=0.05). Conclusion that height of ureum of blood can be happened in oral cavity like the happening of uremic stomatitis.