By polycondensation of triglyceride of saccharin-6-carboxylic acid with some aliphatic diamines, the thermal-stable super-branched polyestersulfoimides – polyglycerides of saccharin-6-carboxylic acid have been obtained. The structures of the synthesized compounds have been confirmed by data of the IR spectroscopy. The yield of the purposeful product was 80–83%. It has been found that the synthesized polyglycerides are well dissolved in polar aprotonic solvents. The thermal stability of the obtained compounds was studied by a method of differential-thermal analysis on derivatograph of system ʺPaulik-Paulik-Erdeyʺ. The derivatographic investigations showed that the synthesized polyglycerides have high thermal stability, decreasing with the growth of length of the aliphatic fragment in their composition. For comparative estimation of the thermal and physical-mechanical indices of the synthesized polyglycerides, the corresponding indices of the industrial polyesterimide Zellamid 1000 have been also given. It has been found that the obtained polyglycerides do not concede to industrial polyesterimides on physical-mechanical indices, but exceed them on thermal stability