In galactic disks, the one dimensional velocity dispersion of <br />
interstellar gas is observed to vary between 12-15 km/s in the central<br />
parts down to 4-6 km/s in the outer regions. Many physical mechanisms <br />
are responsible for generating interstellar turbulence. A prominent one is related to energy feedback from stars particularly in the form of supernova explosions. In this talk, I shall review a number of those mechanisms and using three-dimensional numerical simulations assess the contribution of stellar feedback in the form of supernova explosions to the observed levels of interstellar turbulence at different radii in galactic disks.