Novel farnesylthiosalicylic acid (FTA) derivatives 5a–m with different substituted 1, 3, 4- thiadiazoles were synthesized. Compounds 5b, 5c, 5e and 5f displayed anti-tumor activities superior to FTA in most cancer cells tested. Furthermore, 5e induced tumor cell apoptosis, which was accompanied by lower Bcl-2 expression, but with higher Bax and caspase 3 expression activities in cancer cells.