This study investigated how various H 2 concentrations of fuel mixed with a ceramic granular bed (CGB) affect the propagation characteristics of a premixed C 3 H 8 /air flame. The results showed that at low firing rates (Γ < 1.5 kJ/s), as Γ increased, adding H 2 exerted little effect on the flame temperature and absolute flame front velocity (S ab ); however, at high Γ (Γ > 1.5 kJ/s), as Γ increased, adding H 2 caused a significant decrease in the flame temperature and a substantial increase in S ab. Thus, heat transfer was not obvious, and the flame reaction zone was relatively broad. Although adding H 2 moved the flame reaction zone upstream, the heat transfer mechanism reduced the effect that resulted from adding H 2 under low Γ conditions. Because of the characteristics of H 2 , the flame reaction zones moved upstream, causing the flame thickness and heat loss to increase. Adding H 2 decreased the flame temperature and increased S ab.