Objectives : Aconiti Lateralis Preparata Radix(fuzi, 附子) and its class herbs(chaunwu, caowu etc.) are necessary for some clinical conditions, such as cold pain, chilling etc,. But, they has some poison component. And, they have been known to cause liver and kidney injury, and dangerous in the patients who has abnormal range of LFT and RFT. This study shows the consequences for aspartate aminotransferase(AST), alanine aminotransferase(ALT), blood urea nitrate(BUN), and Creatinine were analyzed using samples from patients who took the decoction containing fuzi. Methods : Blood samples for Experiment Group(E) were collected from 63 patients, who took the decoction containing fuzi, admitted into the 6th internal medicine department of Dong Eui Oriental Medical Hospital between from January 2007 to March 2011. In compared to those of experiment group, blood samples as Control Group(C) were collected from 64 patients, who took the decoction not containing fuzi, admitted into the same hospital from January 2009 to April 2011. Results and Conclusions : 1. AST No changed : E 4.17%, C 2.63%, Increased : E 12.5%, C 28.95%, Decreased : E 80.33%, C 68.42% 2. ALT No changed : E2.94%, C5.13%, Increased : E 8.82%, C 20.51%, Decreased : E 88.24%, C 74.36% 3. BUN No changed : E 0%, CG 7.14%, Increased : E 32.25%, CG 14.29% Decreased : EG 67.65%, CG 78.57% 4. Creatinine No changed : EG 5.00%, CG 0%, Increased : EG 35.00%, CG 54.55% Decreased : EG 60.00%, CG 45.45% 5. The results suggest that the decoction containing fuzi isn't harmful AST, ALT, BUN, Cr of the patients who has high range of them.