Spintronics demands precise control of the storage, manipulation, and transfer of electron spin coherence in solid state systems. In particular, the manipulation of spins in semiconductor materials has become an active area of investigation, where the two main challenges are the enhancement of the electron spin coherence times and the development of spin manipulation techniques that do not compromise the spin lifetime.The book begins with a brief historical introduction about the discover of phenomena of both the giant magnetoresistance and the tunneling magnetoresistance, followed by discussions on the importance of electron spin in semiconductor applications. Moreover, the concepts of spin coherence and spin-coupling are introduced. Section 1 focuses on the properties of dilute magnetic semiconductors and ferromagnetic semiconductors, where in particular, the effect of electric field, a first-principles study and hybrid ferromagnet-semiconductor nanostructures are considered. Section 2 discusses of Rashba/Dresselhaus effects and optical responses of electron spins in semiconductors, with special deepening about the probing of spin splittings by photogalvanic spectroscopy, and electron spin detection by magneto-optical Kerr microscopy. Section 3 present recent works about dynamics, manipulation and transport of spin-polarized electron in magnetic wide-bandgap semiconductors, in III-V semiconductor low dimensional structures and in carbon nanotubes.