The synthesis of butyl heptanoate with n butanol and heptanoic acid as reactants and the rare earth solid super acid SO 2- 4/TiO 2/La 3+ as catalyst had been sutdied.The effects of various actors on the reaction were investigated.The results showed that the appropriate conditions should be:Weight of catalyst is 0.5g(weight of heptanoic acid is 0.2mol);molar ratio of n butanol to heptanoic acid was 1.8∶1;reaction time was 2.0h;dehydrating agent (Toluene) being 15ml.The yield of butyl heptanoate was about 99.2%.