Abstract: The spintronics refers to the research area where electron spins, in additional to or sometimes in place of electron charges, are controlled and manipulated to give rise to an array of properties. Spintronic devices have already found applications in computer hard drive and magnetic random access memory, profoundly changed the information technology industry. These applications utilize the spin polarized transport where electron with fixed spin direction transverse through magnetic heterostructures. More recently, investigation of spin dynamics in spintronic device relates microwave with spin polarized transport, offering significant potential for novel microwave devices with dimension far less than the microwave wavelength. In this “review-like” article, we first briefly introduce the concept of spintronic devices. Microwave experiments with spintronic devices are discussed next in the context of microwave assisted switching and spin pumping phenomenon. The former has potential for developing high density computer hard disk, the latter, with the development of direct electronic detection, could lead to miniaturized and passive microwave detector.