Tri(o-chlorobenzyl)tin 2,4,6-trimethylbenzoate (1) and tri(o-bromobenzyl)tin salicylate (2) were synthesized and characterized by elemental analysis, IR spectroscopy, NMR (¹H, ¹³C and ¹¹⁹Sn), thermogravimetric analysis, and single-crystal X-ray diffraction. The initio calculation and in vitro anticancer activity test were performed for compounds 1 and 2. They are both single tin nucleus structures and the tin atoms were tetracoordinated in a distorted tetrahedral configuration; Compounds 1 and 2 showed stronger anticancer activity than cisplatin in human cervical cancer cells (Hela), liver cancer cells (HuH-7), non-small cell lung cancer cells (A549), lung adenocarcinoma cells (H1975) and breast cancer (MCF-7).