We suggest a new approach to studying atmospheric photochemical processes by analyzing an atmospheric photochemical system as a dynamic system possessing many degrees of freedom and demonstrate a good agreement between the Antarctic photochemical system (APCS) behavior described by a three-order set of ordinary differential equations and ozone variations taking place during ozone hole phenomenon. We investigate the dynamic properties of this set under the parameter values corresponding to the Antarctic stratosphere conditions during the last decade and show that APCS may become unstable as a result of the loss of equilibrium state stability and/or as a result of the self-oscillations appearance. We present some arguments in favor of close connection between the APCS instability and anomalous deep depletion of Antarctic ozone concentration in spring observed since the mid-1980s. ¿ American Geophysical Union 1996