Abstract: To study the expressions of heat shock protein 70 and 90α in nonHodgkin′s lymphoma（NHL）and their clinical significance. MethodsExpressions of HSP70 and HSP90α were evaluated in 30 NHL by immunohistochemical staining.10 necrotic lymphnoditis and 12 reactive hyperplastic lymphnodes were used as controls. ResultsThere were no significant differences in expressions of HSP 70 and HSP90α among NHL, necrotic lymphnoditis, and reactive hyperplastic lymphnodes. High expression of HSP70 （positive cell＞50 %）was correlated with the degree of malignancy, stage and therapy reaction（P＜0.05）, but was not related to B syndrome and extralymphonode infestation（P＞0.05）. No relationship was found between high expression of HSP90α and clinical characters（P＞0.05）. ConclusionHSP70 may be a useful indicator for evaluation of malignancy, stage, and therapy reaction of NHL.

Key words: Heat shock protein 70, Heat shock protein 90α, NonHodgkin′s lymphoma