Abstract: A retrospective review of clinical data was performed in 26 sporadic hepatitis C (SHC) patients and 35 post transfusion hepatitis C (PTHC) cases to compare their clinical features, pathological change and HCV-RNA quantification.The results sho wed that:15 cases in 26 SHC patients were symptomless;Among 22 SHC patients wit h repeated ALT abnormality, only 14 cases with anti-HCV positive had ALT level fr equently over 100U/L, whereas other 8 always below 100U/L;35 PTHC patients had h igher ALT level (over 200U/L) in acute phase, among which 33 cases had repeatedly i ncreased ALT level;The liver tissue pathological examinations showed that the de gree of inflammation in SHC was milder than that in PTHC;The HCV-RNA load in SHC patients was lower than PTHC ones (P<0.05) ;The results indicate that the onset of SHC is hidden and symptom develops slowly The occurrence rate of clini cal symptoms, the level of viral load and the degree of liver injury in SHC are m arkedly lower than those in PTHC.