The rate constants and activation energies for formation of two chemical markers, M-1 and M-2 at sterilization temperatures were determined in a meatball system. Destruction rates for bacterial spores were also determined. The rate constants for M-1 and M-2 formation at $121^{circ}C$ were 0.03 and 0.28 Abs/min, respectively. The activation energies for M-1 and M-2 were 27.9 and 24.6 Cal/mol. M-2 was formed faster than M-1 and reached a maximum and decreased. M-1 formation continued up to 30 min at $121^{circ}C$ and 10 min at $131^{circ}C$, which makes M-1 a more useful chemical marker for high $F_0$ values. The D-values for spores (B. stearothermophilus ATCC 12980) at 111, 114.4, 117.7 and $121^{circ}C$ were 7.5, 4.5, 1.9 and 0.58 respectively. At temperatures between 111 and $121^{circ}C$, there was a liner correlation between destruction of the spores and the M-1 formation. It was difficult to get accurate D-value at $126^{circ}C;and;131^{circ}C$, because almost all spores were dead before temperature at the center of the meatball reached $126^{circ}C$. These data suggest that the chemical marker should be used to evaluate overprocessing as well as microbial lethality in aseptic processing.