Seismic migration methods are developed. Green's theorem is used to derive the Lippmann-Schwinger equation and the following migration methods: phase-shift migration, split-step and PSPI migrations, Fourier Finite Difference migration, phaseencoded multi-source migration, Kirchhoff migration, beam migration, diffraction stacK migration, reverse time migration, and migration velocity analysis. This course is devoted to studying the concept of seismic imaging for exploration purposes. We introduce seismic imaging in the framework of Green's functions and wavefield extrapolation and discuss the various imaging conditions. We look at the various migration methods including Kirchhoff, phase-shift migration, Downward continuation methods, reverse time migration, and others. We discuss the role that velocity plays in the seismic imaging process.