The quality and biochemical properties of honey are affected by heating or during storage period. The most important biochemical reaction that occurs in this process is the Maillard reaction. HMF (5-hydroxymethylfurfural) is one of the major intermediate products in the Maillard reaction that can lead to quality reduction in heated honey. In this study, the effect of heating on the antioxidant activity, and colour values as Maillard reaction indicators of three different botanical honeys were investigated; the HMF formation was also determined. Temperatures of 50, 70 and 80 degrees C were applied on the honeys between 0 and 48h. Total phenolic content, ferric reducing/antioxidant power and scavenging of 2,2-diphenyl-1-picrylhydrazyl free radical assays are used to determine the antioxidant capacity. Results showed that the formation of HMF and the antioxidant properties of honeys were significantly increased during the heating process. Pure HMF compound also showed lower antioxidant activity. The formation of HMF has higher degree of linearity in the fit of the zero order reaction and also it was the highest in the chestnut honey. Furthermore, it was found that as the biochemical value of the honeys increased, the HMF formation decelerated.