[en] The article is devoted to the study of some bi-and tricyclic derivatives of aziridine as materials for new indicators of ionizing radiation. To create high sensitive materials some aspects of photo induced ring opening processes in aziridine derivatives in ethanol solutions and in polymeric matrix were studied and two steps character of the processes investigated was established. Two types of radio indicators were suggested and preliminary tested. The new way of synthesis of radiochromic derivatives of aziridine was developed and series of target compounds synthesized