  We show that fast radio bursts arise from collisions between axion stars and
neutron stars. The bursts are emitted in the atmosphere of the neutron stars.
The observed frequencies of the bursts are given by the axion mass $m_a$ such
as $m_a/2\pi\simeq 1.4\,\mbox{GHz}\,\big(m_a/(6\times 10^{-6}\mbox{eV})\big)$.
From the event rate $\sim 10^{-3}$ per year in a galaxy, we can determine the
mass $\sim 10^{-11}M_{\odot}$ of the axion stars. Using these values we can
explain short durations ( $\sim $ms ) and amount of radiation energies ( $\sim
10^{43}$GeV ) of the bursts.
