The outpu t parameters such as beam divergence angle in far-field output power of high power solid state lasers are variable due to thermal effect of optical pumping. In this paper the dynamic characteristics of various stable and critical resonator configurations, for example, moving rule of working point in the g*-parameter diagram, critical refractive power, critical g*-parameter, beam radius and external far-field divergence angle are investigated in detail using equivalent g*-parameter resonator. The experimental verification and their application are discussed.