  We study how instantons arise in the low energy effective theory of the SU(2)
Yang-Mills theory in the context of the non-linear sigma model recently propose
by Faddeev and Niemi. We find a simple relation between the instanton number
$\nu$ and the charge m of the monopole that appears in the effective theory. It
is given by $\nu = m \Phi/(2\pi)$, where $\Phi$ is the quantized flux
associated with a U(1) gauge field passing through the loop formed by the
singularity of the monopole.
