In solution plasma (SP), the collision of particles (e.g., charged particles, neutral molecules), electron exchange, sputtering of metal surface, vaporization, and generation of ultra-violet (UV) are generally occurred. These phenomena usually result in the formation of reactive species and facilitate chemical reactions. To elucidate, since the components of SP are composed of plasma in gas phase surrounded by liquid phase, there are two reactions routs, previously proposed, including through plasma area where the collision of electrons and ions intensively occurred and through plasma-liquid interface where the chemical reactions are considered to be a heterogeneous reaction. In this chapter, the explanation relating to the reactions in each rout in different solutions, such as aqueous solutions and organic solutions, is provided. Moreover, the synthesis of metal nanoparticles via the SP through different techniques, including reduction of precursor solution and sputtering of metal nanoparticle from electrode surface, is thoroughly described.