Chemiluminescence from thermooxidized epoxide alone and that modified with phenyl glycidyl ethers has been investigated in isothermal and nonisothermal regime. Isothermal curves are characterized by a monotonous fall of chemiluminescence intensity from some initial value to very low levels of light emission. Nonisothermal curves show a maximum intensity at temperatures above 473 K. The luminescence intensity is influenced by both T(g) and thermal stability of epoxide. The higher T(g) or higher thermal stability brings about the higher intensity of light emission and vice versa.