Pseudoprogression occurs in about 30-40% of patients after surgical resection of glioblastoma with radiotherapy and chemotherapy with temozolomide capsules. Pseudoprogression is defined as the enlargement of an existing enhancing lesion or the appearance of a new enhancing lesion soon after radiotherapy. Since this phenomenon is very similar to tumor recurrence, it is called pseudoprogression. Once pseudoprogression occurs, it is not easy to distinguish it from tumor recurrence, which may interfere with the treatment process and even lead to wrong treatment. How to solve it? By stereotactic technique, a biopsy of the lesion can be performed to determine whether it is pseudo-progression or recurrence through pathological diagnosis? The following is a similar case presentation with biopsy confirmed pseudo-progression and current progression-free survival for 30 months. Figure 1 NMR shows residual cavity after tumor resection Figure 2 NMR shows new enhancing lesion at the edge of residual tumor cavity after 1 year Figure 3 CT shows gas at biopsy after stereotactic biopsy, which indirectly confirms the location of biopsy as the location of lesion