1.Relativistic wave equation for Spin-0 particles the klein-gordon equations and its applications. 2.A wave equation for Spin-1/2 particles –the Dirac equations. 3.Lorentz-covariant of the Dirac equations. 4.Spinors under spatial reflection. 5.Bilinear under spatial reflection. 6.Another way of constructing solutions of the free Dirac equations construction by Lorentz transformation. 7.Projection operators for energy and spin. 8.Wave packets of plane Dirac waves. 9.Dirac particles in external fields: examples and problems. 10.The two-center Dirac equations. 11.The foldy- wouthuysen representation for free particles. 12.The hole theory. 13.Klein’s paradox. 14.The Weyl equations – the neutrino 15.Wave equations for particles with arbitrary spins. 16.Lorentz invariance and relativistic symmetry principles.