对５３例星形细胞瘤进行增殖细胞核抗原（ＰＣＮＡ）的免疫组化观察。按照ＤａｕｍａｓＤｕｐｏｒｔ方法，本组病例Ⅱ级星形细胞瘤１４例，Ⅲ级１４例，Ⅳ级２５例；它们的ＰＣＮＡ阳性细胞标记指数分别为２．９９％，９．７３％和３８．０６％。结果表明：ＰＣＮＡ标记指数随着肿瘤组织病理分级的增高而增大，而且小细胞增殖区的标记指数明显高于多形性瘤细胞区。ＰＣＮＡ能反映肿瘤细胞的增殖速率。此项研究可用于判断星形细胞瘤的恶性程度，为临床判断病人的预后提供一个有价值的指标。 Immunohistochemical observation of proliferating cell nuclear antigen (PCNA) in 53 cases of astrocytomas. According to Daumas  Duport method, the group of patients with grade Ⅱ astrocytoma in 14 cases, grade Ⅲ in 14 cases, grade Ⅳ in 25 cases; their PCNA positive cell labeling index were 2.99%, 9.73% and 38.06 %. The results showed that the index of PCNA increased with the increase of histopathological grade of tumor, and the labeling index of small cell proliferation area was significantly higher than that of pleomorphic tumor cell area. PCNA can reflect the proliferation rate of tumor cells. This study can be used to determine the degree of malignancy of astrocytomas and provide a valuable indicator for the clinical judgment of patients’ prognosis.