Abstract: The decomposition curves of TiH2 were determined at different temperatures, and how to decompose TiH2 was studied thermodynamically and kinetically. The way to use TiH2 as foaming agent to prepare aluminum foam was also discussed. The results showed that the decomposition rate of TiH2 increases with increasing temperature, and the decomposition process of TiH2 can be divided into three phases in a certain temperature range. In the range from 620°C to 680°C, the decomposition of TiH2 is violent for 10 min after starting, then the decomposing speed becomes slow during the next 10 min and the decomposition tends to stagnate after 20 min. In the range from 700°C to 720°C, the decomposing speed of TiH2 becomes very rapid for 6 min after starting, then decelerates during the next 4 min and stagnates later.