Abstract: In this research, we review the interaction of oncoming compression shocks. The criteria of transition from regular reflection of oncoming shocks to irregular: Von Neumann criterion and criterion of stationary mach configuration are described. The regions in which the transition from one type of reflection to another is only possible by a shock and regions of fluent transition are described. Dependencies of reflected shock intensity on intensity of interacting oncoming shocks are presented. A range of the problem parameters where the existence of regular and irregular reflection of shock is assumed, explains the possibility of hysteresis.