Five S-(1H-benzotriazol-1-yl)methyl, O,O'-dialkyldithiophosphates were synthesized. Their tribological properties as additives in liquid paraffin were evaluated using a four-ball test machine, and compared with those of zinc dialkyldithiophosphate (T202) and amine salt of thiophosphate complex ester (T307). The results indicate that these compounds possess excellent load-carrying capacity, friction reduction and anti-wear properties similar to those of T202 and T307, and they exhibit better anti-wear properties than T202 and T307 above 294 N load. The thermal stability and corrosive properties of these compounds were also investigated.