Glioblastoma Multiforme (GBM) is most aggressive type of brain tumor in adults. 1,4-dimethyl carbazoles exhibits significant anticancer activities in literature. In this research article, we synthesized a series of novel 1,4-dimethyl-9-H-carbazol-3-yl)methanamine and its derivatives (13-24) and evaluated their in vitro cytotoxicity activities against human glioma U87 MG cell line using MTT assay for 24 h phase time period. All final carbazole derivatives were well confirmed by NMR and HRMS spectroscopy techniques. In series, few compound (15-17) found excellent in vitro anticancer activity (IC50) values 18.50 µM, 47 µM and 75 µM respectively against human glioma U87MG cell line compare to standard drugs used in brain cancer such as Carmustine (IC50 = 18.24 µM) and Temozolomide (IC50 = 100 µM) respectively. Among these derivatives, compound 15 was found to have the most potent cytotoxic effect on tested glioma cell line. This study supported that 1,4-dimethyl-9-H-carbazol-3-yl)methanamine derivatives found significant anticancer potential against human glioma U87MG cell line.