Abstract: In this paper, a comparison of several typical sample preparation systems for ^14C determination is made and an improved conventional sample preparation system proposed by the author is introduced. In the new system, burning unit, digestion unit, gas-purification unit, carbide-synthesis unit, benzene-synthesis unit, as well as temperature and electrocircuit-control unit are well integrated. And simultaneous multi-sample treatment function with advantages of flexibility, conveniency and high efficiency is provided by the new system.