The effects of LiBH4, on the hydrogen absorption performance of magnesium were investigated. A mixture of Mg-LiBH4 with a mass ratio of 4 : 1 was prepared by mechanical milling for 1 h in argon gas. Experimental results show the mixture sample without activation exhibits a very fast kinetics compared with pure magnesium powder. Storage capacities of 7.1% and 6.7% hydrogen for the Mg-LiBH4 composite were achieved in 60 min at 300 °C and 250 °C respectively. It is suggested that LiBH4, may play an important role in the hydrogen storage process of magnesium for kinetic enhancement.