OBJECTIVE:To synthesize ternary complex of rare earth with L-Leucine and imidazoles and to determine its properties.METHODS:The ternary solid complex was synthesized from the reaction of rare earth chlorate with L-Leucine and imidazoles in the medium of alcohol,and the compositional analysis,properties,mechanism of thermolysis,thermostability and the bacteriostatic action of the ternary complex were studied by chemistry analysis,chemical elements analysis,infrared spectral(IR)analysis,molar conductivity measurement and derivative thermogravimetry(TG-DTG)analysis,bioactivity experiments etc.RESULTS:The constitute structure of the ternary complexes was detected to be electrolyte1∶3type RE(Leu) 3 Im(H 2 O)Cl 3 ?2H 2 O,meanwhile,the thermolysis dynamics,thermostability and the bacteriostatic action against E coli of the ternary complex were established preliminarily.CONCLUSION:The composition and the property of the ternary complexes are stable and which were found to be of good bacteriostatic action in the preliminary examination.