In this paper, the chemical structure of aviation perspox have been modified by the copolymerization of two crosslinking agents (allyl methacrylate, diethylene glycol dimthacrylate) with methly methacrylate and methacrylic acid, and four lightly cross linking organic glass plates have been manufactured. Various tests, such as aging stability, heat—mechanical (tensile and impact) properties, transparence, stress—solvent crazing, degree of crosslinking, DMD and infrared spectra of these plates were evaluated and compared with aviation perspex YB3 and YB4 in structure and properties. The results of the studies show that all above—mentioned properties of modified plates is better than aviation perspex YB3 and YB4. So lightly copolymerization—crosslinking is the most effective method to improve heat—mechanical properties and aging—resistence of organic glass plates.