Spins in solids offer the opportunities to develop novel high performance electrical/optical devices. For future spin-based devices, the magnetization reversal without an applied external magnetic field is one of crucial technologies. We have demonstrated to rotate the magnetization of ferromagnetic semiconductor (Ga,Mn)As by hole spin injection with cw circularly polarized light at zero magnetic field. To elucidate the role of hole spins for magnetization rotation, in this research project, we have studied the dynamics of photoinduced magnetization rotation in (Ga,Mn)As by measuring the time-resolved magneto-optical Kerr effect using a femto-second Ti:sapphire laser. Photoinduced magnetization rotation occurs instantaneously within the pulse width (~150 fs), whereas relaxation takes place within tens of ps. The observed behavior leads us to infer the new type of excitation involving the spin complex consisting of coupled hole-Mn spins in hole-induced ferromagnetism. Utilizing (Ga,Mn)As-based quantum well structures, in which the hole spin relaxation time would be prolonged, we have accomplished to enhance the photoinduced magnetization rotation. This opens the possibility to manipulate the magnetization rotation by controlling the carrier dimensionality. We have succeeded, for the first time, the partial magnetization reversal by electrical spin injection in small-size pillar-shaped (Ga,Mn)As-based tunnel magnetoresistance devices.