ObjectiveTo investigate the expression of heat shock proteins 90α(HSP90α) in human hepatocellular carcinoma and the relationship between its expression and biologic behavior of tumor and prognosis. MethodsUsing the immunohistochemical SP method, HSP90α expression was detected in liver tissue from 10 normal individuals, 40 patients with hepatocellular carcinoma(HCC) and adjacent noncancerous liver tissues. ResultsThe positive expression rate of HSP90α was 10.0%,52.5%,72.5% in normal liver tissues,adjacent noncancerous liver tissues,hepatocellular carcinous tissues respectively. A significantly higher distribution of HSP90α positive expression in HCC tissues compared with adjacent noncancerous liver tissues and normal liver tissues was obtained （P＜0.05）. The positive expression of HSP90α in HCC was correlated with clinical stage, tumor differentiation, serosal condition and lymph node metastasis （P＜0.05）, but not to tumor number （P＞0.05）. It was also correlated with prognosis of HCC. The mean tumorfree survival of patients with HSP90α negative expression was 38.6 months while that of HSP90α positive expression was 25.5 months （P＜0.05）. ConclusionHSP90α is overexpressed in human hepatocellular carcinoma. HSP90α could be used as an indicator to judge the clinical stage, tumor differentiation, serosal condition, lymph node metastasis and prognosis of HCC.