An increase in the degradation rate constant (k) with a corresponding decline in the t1/2 values was observed with the increasing temperature at pH 1 and 4. Due to the effect of pH and temperature on the stability of the anthocyanin extract from Thai waxy purple corn cob with the consequence of color changes, it is preferable to apply anthocyanin extract in acidic foods at low temperature to assure stability of color in the products.