We will derive and explore the mass action kinetics of chemical reactions by employing an energetic variational approach. The dynamics of the system is determined through the choice of the free energy, the dissipation (the entropy production), as well as the kimenatics (conservation of species). The method enables us to capture the coupling and competition of various mechanisms, including mechanical effects such as diffusion, viscoelasticity in polymerical fluids and muscle contraction, as well as the thermal effects. This is a joint work with Bob Eisenberg, Pei Liu, Jan-Eric Sulzbach, Yiwei Wang and Tengfei Zhang.