Abstract: On the basis of L-Trp ligand,a series of Fe（Ⅱ）,Co（Ⅱ）,Ni（Ⅱ）,Zn（Ⅱ）,Cd（Ⅱ） and Mn（Ⅱ） M（Ⅱ）-（DL-Trp） coordination polymers were synthesized by a hydrothermal or solvent-thermal or mixed solvent-thermal method.The thermal stability of these coordination polymers was investigated by the thermogravimetric and differential thermal analysis.The results show that the thermal stability of these polymers accords with Irving-Williams law.The radiuses of these divalent metal ions in polymers are less than 0.6.