Abstract: In this article we are prepared heat resistant polymer containing N-(4-Nitro phenyl) maleimide (PNPMI) and Acrylonitile copolymerization under the identical conditions in DMF and THF solvent. The characteristics of the copolymer were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gelpermeation chromatography, and elemental analysis. The thermal stability and degradation mechanism of the copolymer were investigated by Thermogravemetric analysis. Free radical initiator using as an AIBN and BPO in Polymerization reaction , Percentage yield and different solvent system applied and calculated percentage yield. Percentage nitrogen, carbon, and hydrogen content calculate in polymers. The radical polymerization find out by the Polydispersity index. Shape of the polymer in given solution were determined by using range in between according to PDI index. Polymerization process observed by the Polydispersity index. Intrinsic viscosity determined by the using Ubbehold viscometer .Excellent composition structure and Solubility of the Homopolymer and copolymer were determined in different solvent.