A .gamma.-butyrolactone compound as shown in Formula (I) and pharmaceutical composition thereof: ##STR00001## wherein X.dbd.N, O, S, Se; and A and B are selected from substituents having the following formula: ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are selected from a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group, an amino group, an alkoxy group, and a nitro group. The .gamma.-butyrolactone compound and pharmaceutical composition thereof butyrolactone have inhibitory effects on hepatoma, ovarian cancer, breast cancer, lung cancer, malignant glioblastoma or colorectal carcinoma, and are cytotoxic with high specificity to inhibit Paclitaxel-resistant tumour cells at later stage of chemotherapy without any damage on normal cells.