This paper used combine technique of thermogravimetric-differentical thermal analysis(TG-DTA) to study the volatility, the thermal stability, the relation between the properties of metal ion and heat of twenty-one metal-diethyldithiocarbamate chelates. Also the gas chromatographic behavior of these Chelates have leen studied systematically. Among of them the thermal properties of T1(Ⅰ), Se(Ⅳ), Au(Ⅰ), MoO,2,(Ⅱ) chelates and the gas chromatographic study of T1(Ⅰ), Se(Ⅳ) chelates have not been published.