A series of novel metal (Ca, Sr, Ba, Zn, Co, Ni, Pb) bismaleimide monomers [BMI(M)] was prepared by reaction of maleic anhydride and metal diamines. The thermal cyclodehydration of the precursors of the bismaleimides was studied by TG-DTA, IR and H-1 NMR spectrometry. It was found that the thermal stability of BMI(M) is dependent on the nature of the metal, and has the following order in air as indicated by T-d (the temperature of initial decomposition from the TG curves) : BMI(Sr) > BMI(Ba) > BMI(Co) > BMI(Pb)> BMI(Zn) > BMI(Ca) > BMI(Ni).