M87, possibly the most studied relativistic jet in active radio galaxies, has been spatially resolved from ten to tens of millions of Schwarzschild radii; it gives a unique opportunity for understanding an AGN jet from birth to termination. Several key issues in AGN jets can be extensively discussed based on multi-frequency radio observations and magnetohydrodynamic (MHD) jet theories toward M87. One of our remarkable findings in M87 is the "jet break", a structural change from parabolic to conical geometry, which coincides to a transition from increasing to decreasing in observed proper motions. In this talk, we discuss about the jet break as a fundamental property in AGNs under the interplay with the SMBH growth and evolution of early-type galaxies.