Abstract: Lightly sonicated E. gracilis cells were extracted sequentially, and then their nuclear matrix and nuclear lamina were investigated by DGD embedment-free electron microscopy and Western blot analysis. The results showed that in the nucleus there were a fibrous network and a layer of lamina beneath the nuclear membrane, both of which could not be removed by DNase and hot trichloroacetic acid. Western blot analysis(with polyclonal antiserum against three lamins of rat liver)showed that its nuclear lamina possessed a major and a minor positive polypeptides, which were similar to mammalian lamin B and lamin A respectively. It was suggested that the lower unicellular eukaryote E. gracilis already had nuclear matrix and nuclear lamina, its lamina polypeptide(lamin)should reflect a historical stage of nuclear lamina evolution.