As an extension of our previous study, this paper reports a new type of oscillatory reaction system: DL-malic acid (abbreviated to DL-MA)- CH~3COCH~3 (abbreviated to Act)-Mn^2^+-H~2SO~4, and all factors that affect the reaction. The role of each reactant in the inductory phase, the cause of oscillation, the new characteristics of the inductory phase and possible mechanism of oscillatory reaction have been investigated. The simulation equations in which the inductory phase is affected by concentration of DL-MA, KBrO~3 and MnSO~4 are obtained. The activation parameter of the inductory phase, E~I~N is 68.50kJ· mol^-^1.

Key words: OSCILLATION CHEMICAL REACTION, INCUBATION PERIOD, MALIC ACID, ACETONE, REACTION MECHANISM, KINETIC STUDY