The violent dynamical expansion of dense matter produced in heavy-ion collisions determines that the microscopic transport theories designed for it should keep the line of time evolution and medium effects, both in the in-medium particle drifting and in-medium particle-particle scatterings. A set of relativistic transport equations for particle distribution functions have thus been developed. Starting from a Lagrangian of baryons interacting through mesons, one computes Feynman diagrams up to the Born term through employing the closed time-path Green's function technique. All the ingredients of equations are derived from the same effective interaction and presented analytically. This book clearly shows how a relativistic Boltzmann equation can be deduced from a given interaction through reckoning Feynman diagrams of quantum field theory. While discussions are concentrated on the topic of relativistic heavy-ion collisions, the introduced method is rather general, and may find it's application in the problems of neutrino transportation of astrophysics and electron transportation of solid-state physics.