Preparation of TiAl–Ti 5 Si 3 and TiAl–Al 2 O 3 in situ composites with a broad range of composition was conducted by self-propagating high-temperature synthesis (SHS). Sample compacts containing Ti, Al, and TiO 2 powders were employed to produce the TiAl–matrix composite reinforced by Al 2 O 3 , which was yielded through the displacement reaction of Al with TiO 2 . On the other hand, elemental powder compacts were used to synthesize the TiAl–matrix composite with Ti 5 Si 3 as the reinforcement. Experimental observations show that the addition of Si in the Ti–Al powder mixture enhances the sustainability of the reaction and the increase of Ti 5 Si 3 formed in the composite increases the combustion temperature and combustion wave velocity. However, the opposite trends were found in the synthesis of TiAl–Al 2 O 3 composites. Not only is a preheating temperature of 300°C required to achieve self-sustaining combustion, but also the reaction temperature and flame-front propagation rate decrease with Al 2 O 3 content. Moreover, it was found that the combustion front propagated in a pulsating mode when the mole fraction of Al 2 O 3 higher than 12.5mol% was produced, because of the lower exothermicity of the reaction between Al and TiO 2 than that of Ti with Al. The Al 2 O 3 content of the TiAl–Al 2 O 3 composite obtained by this study has an upper limit at 28.6mol%, beyond which combustion ceased to propagate. The XRD analysis of the end products confirms formation of TiAl–Ti 5 Si 3 and TiAl–Al 2 O 3 in situ composites. In addition to TiAl, another aluminide compound Ti 3 Al known as a major secondary phase in the Ti–Al reaction was detected in both types of the composites.