BACKGROUND: Meningiomas are one of the most common benign tumors in the intracranial field, and clinical treatment is mainly surgery. However, the postoperative recurrence rate is high, and other treatment modalities do not yet have a definite effect, so the exploration of new targeted drugs is promising for meningioma treatment. At present, the pathogenesis of autophagy in benign meningiomas is not very clear, and a large number of experiments are still needed for in-depth study. OBJECTIVE: To investigate the ultrastructural features and clinical significance of autophagy in benign meningiomas. METHODS: Meningiomas were diagnosed by light microscopy with different subtyping. Diagnosis and typing of meningiomas were aided by transmission electron microscopy, and the ultrastructural morphology and number of autophagosomes in the cytoplasm of meningioma cells of different grades were observed. Western blot assay was used to detect the expression levels of autophagy-related proteins Beclin1 and LC3 in different grades of meningiomas. The altered expression of Vimentin, EMA, PR, S-100 and GFAP in meningiomas was evaluated by immunohistochemical staining. RESULTS AND CONCLUSION: 176 meningiomas were identified, including 98 males and 78 females. (1) Histopathological types CNS WHO grade 1 benign meningiomas comprised a total of 168 cases, including 62 cases of meningocortical type, 36 cases of fibrous type, 58 cases of transitional type, 12 cases of angiomatous type, 4 cases of CNS WHO grade 2 clear cell type, 2 cases of atypical type, and 2 cases of WHO grade 3 anaplastic lesions. (2) Transmission electron microscopy revealed autophagic bodies in 27 cases of WHO grade 1 meningiomas, and no autophagic bodies were detected in WHO grades 2 and 3 meningiomas. (3) LC3 and Beclin1 were highly expressed in WHO grade 1 benign meningiomas by western blot assay and were negatively expressed in WHO grades 2 and 3 meningiomas. (4) The immunohistochemical markers Vimentin, EMA, and PR, were expressed to various degrees, while GFAP and S-100 were negative. (5) A combination of electron microscopy, immunohistochemical staining and western blot assay showed that autophagy only plays an important role in the occurrence and development of WHO grade 1 benign meningiomas. [ABSTRACT FROM AUTHOR]