  Blazars are well known for the violent variability from the radio to
gamma-ray wavelengths. In this paper, we present a brief summary of the X-ray
variability recently obtained for TeV blazars. We also point out the probable
similarities of the X-ray variability characteristics between blazars and
microblazars. Such phenomenological analogies could be interpreted and unified
with the synchrotron X-ray emissions from the jets of the two classes of
objects that differ in black hole mass by factors of $\ga 10^7$. The
phenomenological analogies in blazars and microblazars (both are jet-dominated)
might be parallel to those in black hole X-ray binaries in high/soft state and
Seyfert galaxies (both are disk-dominated).
