The hydrogen storage properties of TiFe and its alloys, partially substituted by Mn or A1 for Fe were studied. Sievert`s type apparatus and high pressure autoclave were used. When Fe is partially substituted by Mn, the hydrogen storage capacity is little changed and the stability of the hydride was slightly increased ans activation is promoted. Partial substitution by Al promotes activation markedly but reduces hydrogen storage capacity significantly. Enthalpy changes of hydride formation calculated by applying Lutz`s are in good agreement with those from experiment in TiFe_(l-x)Mn_(x-)H system. The cracking phenomena on hydride formation is closely related to activation procedure.